// ValidateForm.js
//
// This is a set of JavaScript functions for validating input on 
// an HTML form.  Functions are provided to validate:
//	
//	function isEmpty(s)						// Check whether string s is empty.
//	function isWhitespace(s)				// Returns true if string s is empty or whitespace characters only.
//	function isLetter (c)					// Returns true if character c is an English letter (A .. Z, a..z).
//	function isDigit(c)						// Returns true if character c is a digit (0 .. 9).
//	function isLetterOrDigit(c)				// Returns true if character c is a letter or digit.
//	function isInteger(s)					// Returns true if all characters in string s are numbers.
//	function isIntegerInRange(s, a, b)		// Returns true if string s is an integer within the range of integer arguments a and b, inclusive.
//	function isSignedInteger(s)				// Returns true if all characters are numbers
//	function isPositiveInteger(s)			// Returns true if string s is an integer > 0.
//	function isNonnegativeInteger(s)		// Returns true if string s is an integer >= 0.
//	function isNegativeInteger(s)			// Returns true if string s is an integer < 0.
//	function isNonpositiveInteger(s)		// Returns true if string s is an integer <= 0.
//	function isFloat(s)						// True if string s is an unsigned floating point (real) number. 
//	function isSignedFloat(s)				// True if string s is a signed or unsigned floating point (real) number. First character is allowed to be + or -.
//	function isAlphabetic (theField, fieldName, emptyOK)		// Returns true if string s is English letters (A .. Z, a..z) only.
//	function isAlphanumeric(s)				// Returns true if string s is English letters (A .. Z, a..z) and numbers only.
//	
//	function stripCharsInBag(s, bag)		// Removes all characters which appear in string bag from string s.
//	function stripCharsNotInBag(s, bag)		// Removes all characters which do NOT appear in string bag from string s.
//	function stripWhitespace(s)				// Removes all whitespace characters from s.  
//	function stripInitialWhitespace(s)		// Removes initial (leading) whitespace characters from s.
//	
//	function isUSPhoneNumber(s)				// Returns true if string s is a valid U.S. Phone Number.
//	function isZIPCode(s)					// isZIPCode returns true if string s is a valid U.S. ZIP code. 
//	function isStateCode(s)					// Return true if s is a valid U.S. Postal Code (abbreviation for state).
//	function isEmail(s)						// Return true if s is in a form of a@b.c
//	function isYear (s)						// Returns true if s is a valid Year number.
//	function isMonth(s)						// Returns true if string s is a valid Month number between 1 and 12.
//	function isDay(s)						// isDay returns true if string s is a valid Day number between 1 and 31.
//	function daysInFebruary(year)			// Given integer argument year, returns number of days in February of that year.
//	function isDate(year, month, day)		// Returns true if string arguments year, month, and day form a valid date
//	
//	function prompt(s)						// Display prompt string s in status bar.
//	function promptEntry(s)					// Display data entry prompt string s in status bar.
//	function warnEmpty(theField, s)			// Notify user that required field theField is empty.
//	function warnInvalid(theField, s)		// Notify user that contents of field theField are invalid.
//	
//	function checkString(theField, s, emptyOK)		// Check that string theField.value is not all whitespace.
//	function checkStringLength(theField, s, length)	// Check that string theField.value is not all whitespace.
//	function checkSelect(theField, s, index, emptyOK)						// Check that select theField was selected.
//	function checkStateCode(theField, emptyOK)		// Check that string theField.value is a valid U.S. state code.
//	function checkZIPCode(theField, emptyOK)		// Check that string theField.value is a valid ZIP code.
//	function checkZIPCode2(theField5, theField4, emptyOK)					// Check that string theField5.value is a valid 5 digit ZIP code, and the string theField4.value (optionally) contains a valid 4 digit ZIP extension
//	function checkUSPhone(theField, emptyOK)		// Check that string theField.value is a valid US Phone.
//	function checkUSPhone2(theField1, theField2, theField3, emptyOK)		// Check that string theField1.value is a valid 3 digit area code, and the string theField2.value is a valid 3 digit exchange and the string theField3.value is a valid 4 digit number.
//	function checkEmail(theField, emptyOK)			// Check that string theField.value is a valid Email.
//	function checkYear(theField, emptyOK)			// Check that string theField.value is a valid Year.
//	function checkMonth(theField, emptyOK)			// Check that string theField.value is a valid Month.
//	function checkDay(theField, emptyOK)			// Check that string theField.value is a valid Day.
//	function checkDate(yearField, monthField, dayField, labelString, OKtoOmitDay)		// Check that yearField.value, monthField.value, and dayField.value form a valid date.
//	function checkGSAContract(theField, emptyOK)	// Check GSA contract number formatting
//	function checkURL(urlctrl, name)				// Check URL formatting
//	function checkURL2(url)							// Check URL formatting, alert if empty
//	function checkWebsite(urlctrl, name)			// Check Website formatting
//	function checkPassword(pwd)						// Check password
//	function checkTwoPasswords(theField1, theField2)						// Check password and confirm password 
//	
//	function reformat (s)					// Function for arbitrarily inserting formatting characters or delimiters of various kinds within TARGETSTRING.
//	function reformatZIPCode (ZIPString)	// Takes ZIPString, a string of 5 or 9 digits; if 9 digits, inserts separator hyphen
//	function reformatUSPhone(USPhone)		// Takes USPhone, a string of 10 digits and reformats as (123) 456-789
//	function formatURL(ctl)					// Format URL
//	
//	function getRadioButtonValue(radio)		// Get checked value from radio button.  
//	function toggleCheckbox(cbox)			// Toggle checkbox value
//	
//	function processKeyUp(field1, length, field2)	// Move focus to field2 after length characters are typed into field1 
//

// VARIABLE DECLARATIONS
var whitespace = " \t\n\r";
var digits = "0123456789";
var lowercaseLetters = "abcdefghijklmnopqrstuvwxyz"
var uppercaseLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"


// non-digit delimiters
var ZIPCodeDelimiters = "-";
var SSNDelimiters = "- ";
var phoneNumberDelimiters = "()-x ";
var decimalPointDelimiter = "."
var USStateCodeDelimiter = "|";
var creditCardDelimiters = " "


// CONSTANT STRING DECLARATIONS
var mPrefix = "You did not enter a value into the "
var mSuffix = " field. This is a required field. Please enter it now."


// useful constants
var digitsInSocialSecurityNumber = 9;
var digitsInUSPhoneNumber = 10;
var digitsInZIPCode1 = 5
var digitsInZIPCode2 = 9
var daysInMonth = new Array(31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
var USStateCodes = "AL|AK|AS|AZ|AR|CA|CO|CT|DE|DC|FM|FL|GA|GU|HI|ID|IL|IN|IA|KS|KY|LA|ME|MH|MD|MA|MI|MN|MS|MO|MT|NE|NV|NH|NJ|NM|NY|NC|ND|MP|OH|OK|OR|PW|PA|PR|RI|SC|SD|TN|TX|UT|VT|VI|VA|WA|WV|WI|WY|AE|AA|AE|AE|AP"
var validWorldPhoneChars = digits + phoneNumberDelimiters + "+";
var validSSNChars = digits + SSNDelimiters;
var validZIPCodeChars = digits + ZIPCodeDelimiters


// Global variable defaultEmptyOK defines default return value 
// for many functions when they are passed the empty string. 
// By default, they will return defaultEmptyOK.
var defaultEmptyOK = false


// s is an abbreviation for "string"
var sUSLastName = "Last Name"
var sUSFirstName = "First Name"
var sWorldLastName = "Family Name"
var sWorldFirstName = "Given Name"
var sTitle = "Title"
var sCompanyName = "Company Name"
var sUSAddress = "Street Address"
var sWorldAddress = "Address"
var sCity = "City"
var sStateCode = "State Code"
var sWorldState = "State, Province, or Prefecture"
var sCountry = "Country"
var sZIPCode = "ZIP Code"
var sWorldPostalCode = "Postal Code"
var sPhone = "Phone Number"
var sFax = "Fax Number"
var sDateOfBirth = "Date of Birth"
var sExpirationDate = "Expiration Date"
var sEmail = "Email"
var sSSN = "Social Security Number"
var sCreditCardNumber = "Credit Card Number"
var sOtherInfo = "Other Information"


// p is an abbreviation for "prompt"
var pEntryPrompt = "Please enter a "
var pStateCode = "2 character code (like CA)."
var pZIPCode = "5 or 9 digit U.S. ZIP Code (like 94043)."
var pUSPhone = "10 digit U.S. phone number (like 415 555 1212)."
var pWorldPhone = "international phone number."
var pSSN = "9 digit U.S. social security number (like 123 45 6789)."
var pEmail = "valid email address (like foo@bar.com)."
var pCreditCard = "valid credit card number."
var pDay = "day number between 1 and 31."
var pMonth = "month number between 1 and 12."
var pYear = "2 or 4 digit year number."


// Error messages
var iStateCode = "This field must be a valid two character U.S. state abbreviation (like CA for California). Please reenter it now."
var iZIPCode = "ZIP Code must be a 5 or 9 digit U.S. ZIP Code. Please reenter it now."
var iUSPhone = "Phone must be a 10 digit U.S. phone number (like 415 555 1212). Please reenter it now."
var iWorldPhone = "This field must be a valid international phone number. Please reenter it now."
var iSSN = "This field must be a 9 digit U.S. social security number (like 123 45 6789). Please reenter it now."
var iEmail = "This field must be a valid email address (like name@address.com). Please reenter it now."
var iCreditCardPrefix = "This is not a valid "
var iCreditCardSuffix = " credit card number. (Click the link on this form to see a list of sample numbers.) Please reenter it now."
var iDay = "This field must be a day number between 1 and 31.  Please reenter it now."
var iMonth = "This field must be a month number between 1 and 12.  Please reenter it now."
var iYear = "This field must be a 2 or 4 digit year number.  Please reenter it now."
var iDatePrefix = "The Day, Month, and Year for "
var iDateSuffix = " do not form a valid date.  Please reenter them now."


// Check whether string s is empty.
function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}


// Returns true if string s is empty or 
// whitespace characters only.
function isWhitespace(s)
{   var i;

    // Is s empty?
    if (isEmpty(s)) return true;

    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);

        if (whitespace.indexOf(c) == -1) return false;
    }

    // All characters are whitespace.
    return true;
}


// Removes all characters which appear in string bag from string s.
function stripCharsInBag(s, bag)
{   var i;
    var returnString = "";

    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }

    return returnString;
}


// Removes all characters which do NOT appear in string bag 
// from string s.
function stripCharsNotInBag(s, bag)
{   var i;
    var returnString = "";

    // Search through string's characters one by one.
    // If character is in bag, append to returnString.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) != -1) returnString += c;
    }

    return returnString;
}


// Removes all whitespace characters from s.
// Global variable whitespace (see above)
// defines which characters are considered whitespace.
function stripWhitespace(s)
{   return stripCharsInBag (s, whitespace)
}


// Removes initial (leading) whitespace characters from s.
// Global variable whitespace (see above)
// defines which characters are considered whitespace.
function stripInitialWhitespace(s)
{   var i = 0;

	while ((i < s.length) && (whitespace.indexOf(s.charAt(i)) != -1))
	   i++;
    
    return s.substring (i, s.length);
}


// Returns true if character c is an English letter 
// (A .. Z, a..z).
//
// NOTE: Need i18n version to support European characters.
// This could be tricky due to different character
// sets and orderings for various languages and platforms.

function isLetter (c)
{   return ( ((c >= "a") && (c <= "z")) || ((c >= "A") && (c <= "Z")) )
}


// Returns true if character c is a digit 
// (0 .. 9).
function isDigit(c)
{   return ((c >= "0") && (c <= "9"))
}


// Returns true if character c is a letter or digit.
function isLetterOrDigit(c)
{   return (isLetter(c) || isDigit(c))
}


// isInteger (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if all characters in string s are numbers.
//
// Accepts non-signed integers only. Does not accept floating 
// point, exponential notation, etc.
//
// We don't use parseInt because that would accept a string
// with trailing non-numeric characters.
//
// By default, returns defaultEmptyOK if s is empty.
// There is an optional second argument called emptyOK.
// emptyOK is used to override for a single function call
//      the default behavior which is specified globally by
//      defaultEmptyOK.
// If emptyOK is false (or any value other than true), 
//      the function will return false if s is empty.
// If emptyOK is true, the function will return true if s is empty.
//
// EXAMPLE FUNCTION CALL:     RESULT:
// isInteger ("5")            true 
// isInteger ("")             defaultEmptyOK
// isInteger ("-5")           false
// isInteger ("", true)       true
// isInteger ("", false)      false
// isInteger ("5", false)     true
function isInteger(s)
{   var i;

    if (isEmpty(s)) 
       if (isInteger.arguments.length == 1) return defaultEmptyOK;
       else return (isInteger.arguments[1] == true);

    // Search through string's characters one by one
    // until we find a non-numeric character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);

        if (!isDigit(c)) return false;
    }

    // All characters are numbers.
    return true;
}


// isIntegerInRange (STRING s, INTEGER a, INTEGER b [, BOOLEAN emptyOK])
// 
// isIntegerInRange returns true if string s is an integer 
// within the range of integer arguments a and b, inclusive.
// 
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isIntegerInRange(s, a, b)
{   if (isEmpty(s)) 
       if (isIntegerInRange.arguments.length == 1) return defaultEmptyOK;
       else return (isIntegerInRange.arguments[1] == true);

    // Catch non-integer strings to avoid creating a NaN below,
    // which isn't available on JavaScript 1.0 for Windows.
    if (!isInteger(s, false)) return false;

    // Now, explicitly change the type to integer via parseInt
    // so that the comparison code below will work both on 
    // JavaScript 1.2 (which typechecks in equality comparisons)
    // and JavaScript 1.1 and before (which doesn't).
    var num = parseInt (s);
    return ((num >= a) && (num <= b));
}


// isSignedInteger (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if all characters are numbers; 
// first character is allowed to be + or - as well.
//
// Does not accept floating point, exponential notation, etc.
//
// We don't use parseInt because that would accept a string
// with trailing non-numeric characters.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
//
// EXAMPLE FUNCTION CALL:          RESULT:
// isSignedInteger ("5")           true 
// isSignedInteger ("")            defaultEmptyOK
// isSignedInteger ("-5")          true
// isSignedInteger ("+5")          true
// isSignedInteger ("", false)     false
// isSignedInteger ("", true)      true
function isSignedInteger(s)
{   if (isEmpty(s)) 
       if (isSignedInteger.arguments.length == 1) return defaultEmptyOK;
       else return (isSignedInteger.arguments[1] == true);

    else {
        var startPos = 0;
        var secondArg = defaultEmptyOK;

        if (isSignedInteger.arguments.length > 1)
            secondArg = isSignedInteger.arguments[1];

        // skip leading + or -
        if ( (s.charAt(0) == "-") || (s.charAt(0) == "+") )
           startPos = 1;    
        return (isInteger(s.substring(startPos, s.length), secondArg))
    }
}


// isPositiveInteger (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if string s is an integer > 0.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isPositiveInteger(s)
{   var secondArg = defaultEmptyOK;

    if (isPositiveInteger.arguments.length > 1)
        secondArg = isPositiveInteger.arguments[1];

    // The next line is a bit byzantine.  What it means is:
    // a) s must be a signed integer, AND
    // b) one of the following must be true:
    //    i)  s is empty and we are supposed to return true for
    //        empty strings
    //    ii) this is a positive, not negative, number

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) > 0) ) );
}


// isNonnegativeInteger (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if string s is an integer >= 0.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isNonnegativeInteger(s)
{   var secondArg = defaultEmptyOK;

    if (isNonnegativeInteger.arguments.length > 1)
        secondArg = isNonnegativeInteger.arguments[1];

    // The next line is a bit byzantine.  What it means is:
    // a) s must be a signed integer, AND
    // b) one of the following must be true:
    //    i)  s is empty and we are supposed to return true for
    //        empty strings
    //    ii) this is a number >= 0

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) >= 0) ) );
}


// isNegativeInteger (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if string s is an integer < 0.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isNegativeInteger(s)
{   var secondArg = defaultEmptyOK;

    if (isNegativeInteger.arguments.length > 1)
        secondArg = isNegativeInteger.arguments[1];

    // The next line is a bit byzantine.  What it means is:
    // a) s must be a signed integer, AND
    // b) one of the following must be true:
    //    i)  s is empty and we are supposed to return true for
    //        empty strings
    //    ii) this is a negative, not positive, number

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) < 0) ) );
}


// isNonpositiveInteger (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if string s is an integer <= 0.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isNonpositiveInteger(s)
{   var secondArg = defaultEmptyOK;

    if (isNonpositiveInteger.arguments.length > 1)
        secondArg = isNonpositiveInteger.arguments[1];

    // The next line is a bit byzantine.  What it means is:
    // a) s must be a signed integer, AND
    // b) one of the following must be true:
    //    i)  s is empty and we are supposed to return true for
    //        empty strings
    //    ii) this is a number <= 0

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) <= 0) ) );
}


// isFloat (STRING s [, BOOLEAN emptyOK])
// 
// True if string s is an unsigned floating point (real) number. 
//
// Also returns true for unsigned integers. If you wish
// to distinguish between integers and floating point numbers,
// first call isInteger, then call isFloat.
//
// Does not accept exponential notation.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isFloat(s)
{   var i;
    var seenDecimalPoint = false;

    if (isEmpty(s)) 
       if (isFloat.arguments.length == 1) return defaultEmptyOK;
       else return (isFloat.arguments[1] == true);

    if (s == decimalPointDelimiter) return false;

    // Search through string's characters one by one
    // until we find a non-numeric character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);

        if ((c == decimalPointDelimiter) && !seenDecimalPoint) seenDecimalPoint = true;
        else if (!isDigit(c)) return false;
    }

    // All characters are numbers.
    return true;
}


// isSignedFloat (STRING s [, BOOLEAN emptyOK])
// 
// True if string s is a signed or unsigned floating point 
// (real) number. First character is allowed to be + or -.
//
// Also returns true for unsigned integers. If you wish
// to distinguish between integers and floating point numbers,
// first call isSignedInteger, then call isSignedFloat.
//
// Does not accept exponential notation.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isSignedFloat(s)
{   if (isEmpty(s)) 
       if (isSignedFloat.arguments.length == 1) return defaultEmptyOK;
       else return (isSignedFloat.arguments[1] == true);

    else {
        var startPos = 0;
        var secondArg = defaultEmptyOK;

        if (isSignedFloat.arguments.length > 1)
            secondArg = isSignedFloat.arguments[1];

        // skip leading + or -
        if ( (s.charAt(0) == "-") || (s.charAt(0) == "+") )
           startPos = 1;    
        return (isFloat(s.substring(startPos, s.length), secondArg))
    }
}


// isAlphabetic (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if string s is English letters 
// (A .. Z, a..z) only.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
//
// NOTE: Need i18n version to support European characters.
// This could be tricky due to different character
// sets and orderings for various languages and platforms.
function isAlphabetic (theField, fieldName, emptyOK)
{
	if (isAlphabetic.arguments.length == 2) emptyOK = defaultEmptyOK;   
	if ((emptyOK == true) && (isEmpty(theField.value))) return true;
	if ((emptyOK == false) && (isEmpty(theField.value)))
		return warnInvalid(theField, fieldName + " is a required field.");
	var i;
	s = theField.value;
    if (isEmpty(s))
       if (isAlphabetic.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphabetic.arguments[1] == true);

    // Search through string's characters one by one
    // until we find a non-alphabetic character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is letter.
        var c = s.charAt(i);

        if (!isLetter(c))
        return warnInvalid(theField,"Non-alpha characters are not permitted in " + fieldName);
	//return false;
    }

    // All characters are letters.
    return true;
}


// isAlphanumeric (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if string s is English letters 
// (A .. Z, a..z) and numbers only.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
//
// NOTE: Need i18n version to support European characters.
// This could be tricky due to different character
// sets and orderings for various languages and platforms.
function isAlphanumeric(s)
{   var i;

    if (isEmpty(s)) 
       if (isAlphanumeric.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphanumeric.arguments[1] == true);

    // Search through string's characters one by one
    // until we find a non-alphanumeric character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number or letter.
        var c = s.charAt(i);

        if (! (isLetter(c) || isDigit(c) ) )
        return false;
    }

    // All characters are numbers or letters.
    return true;
}


// reformat (TARGETSTRING, STRING, INTEGER, STRING, INTEGER ... )       
//
// Handy function for arbitrarily inserting formatting characters
// or delimiters of various kinds within TARGETSTRING.
//
// reformat takes one named argument, a string s, and any number
// of other arguments.  The other arguments must be integers or
// strings.  These other arguments specify how string s is to be
// reformatted and how and where other strings are to be inserted
// into it.
//
// reformat processes the other arguments in order one by one.
// * If the argument is an integer, reformat appends that number 
//   of sequential characters from s to the resultString.
// * If the argument is a string, reformat appends the string
//   to the resultString.
//
// NOTE: The first argument after TARGETSTRING must be a string.
// (It can be empty.)  The second argument must be an integer.
// Thereafter, integers and strings must alternate.  This is to
// provide backward compatibility to Navigator 2.0.2 JavaScript
// by avoiding use of the typeof operator.
//
// It is the caller's responsibility to make sure that we do not
// try to copy more characters from s than s.length.
//
// EXAMPLES:
//
// * To reformat a 10-digit U.S. phone number from "1234567890"
//   to "(123) 456-7890" make this function call:
//   reformat("1234567890", "(", 3, ") ", 3, "-", 4)
//
// * To reformat a 9-digit U.S. Social Security number from
//   "123456789" to "123-45-6789" make this function call:
//   reformat("123456789", "", 3, "-", 2, "-", 4)
//
// HINT:
//
// If you have a string which is already delimited in one way
// (example: a phone number delimited with spaces as "123 456 7890")
// and you want to delimit it in another way using function reformat,
// call function stripCharsNotInBag to remove the unwanted 
// characters, THEN call function reformat to delimit as desired.
//
// EXAMPLE:
//
// reformat (stripCharsNotInBag ("123 456 7890", digits),
//           "(", 3, ") ", 3, "-", 4)
function reformat (s)
{   var arg;
    var sPos = 0;
    var resultString = "";

    for (var i = 1; i < reformat.arguments.length; i++) {
       arg = reformat.arguments[i];
       if (i % 2 == 1) resultString += arg;
       else {
           resultString += s.substring(sPos, sPos + arg);
           sPos += arg;
       }
    }
    return resultString;
}


// isUSPhoneNumber (STRING s [, BOOLEAN emptyOK])
// 
// isUSPhoneNumber returns true if string s is a valid U.S. Phone
// Number.  Must be 10 digits.
//
// NOTE: Strip out any delimiters (spaces, hyphens, parentheses, etc.)
// from string s before calling this function.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isUSPhoneNumber(s)
{   if (isEmpty(s)) 
       if (isUSPhoneNumber.arguments.length == 1) return defaultEmptyOK;
       else return (isUSPhoneNumber.arguments[1] == true);
    return (isInteger(s) && s.length >= 10)
}


// isZIPCode (STRING s [, BOOLEAN emptyOK])
// 
// isZIPCode returns true if string s is a valid 
// U.S. ZIP code.  Must be 5 or 9 digits only.
//
// NOTE: Strip out any delimiters (spaces, hyphens, etc.)
// from string s before calling this function.  
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isZIPCode(s)
{  if (isEmpty(s)) 
       if (isZIPCode.arguments.length == 1) return defaultEmptyOK;
       else return (isZIPCode.arguments[1] == true);
   return (isInteger(s) && 
            ((s.length == 5) ||
             (s.length == 9)))
}


// isStateCode (STRING s [, BOOLEAN emptyOK])
// 
// Return true if s is a valid U.S. Postal Code 
// (abbreviation for state).
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isStateCode(s)
{   if (isEmpty(s)) 
       if (isStateCode.arguments.length == 1) return defaultEmptyOK;
       else return (isStateCode.arguments[1] == true);
    return ( (USStateCodes.indexOf(s) != -1) &&
             (s.indexOf(USStateCodeDelimiter) == -1) )
}


// isEmail (STRING s [, BOOLEAN emptyOK])
// 
// Email address must be of form a@b.c -- in other words:
// * there must be at least one character before the @
// * there must be at least one character before and after the .
// * the characters @ and . are both required
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isEmail(s)
{   if (isEmpty(s)) 
       if (isEmail.arguments.length == 1) return defaultEmptyOK;
       else return (isEmail.arguments[1] == true);
   
    // is s whitespace?
    if (isWhitespace(s)) return false;
    
    // there must be >= 1 character before @, so we
    // start looking at character position 1 
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;

    // look for @
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }

    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;

    // look for .
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }

    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}


// isYear (STRING s [, BOOLEAN emptyOK])
// 
// isYear returns true if string s is a valid 
// Year number.  Must be 2 or 4 digits only.
// 
// For Year 2000 compliance, you are advised
// to use 4-digit year numbers everywhere.
//
// And yes, this function is not Year 10000 compliant, but 
// because I am giving you 8003 years of advance notice,
// I don't feel very guilty about this ...
//
// For B.C. compliance, write your own function. ;->
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isYear (s)
{   if (isEmpty(s)) 
       if (isYear.arguments.length == 1) return defaultEmptyOK;
       else return (isYear.arguments[1] == true);
    if (!isNonnegativeInteger(s)) return false;
    return ((s.length == 2) || (s.length == 4));
}


// isMonth (STRING s [, BOOLEAN emptyOK])
// 
// isMonth returns true if string s is a valid 
// month number between 1 and 12.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isMonth(s)
{   if (isEmpty(s)) 
       if (isMonth.arguments.length == 1) return defaultEmptyOK;
       else return (isMonth.arguments[1] == true);
    return isIntegerInRange (s, 1, 12);
}


// isDay (STRING s [, BOOLEAN emptyOK])
// 
// isDay returns true if string s is a valid 
// day number between 1 and 31.
// 
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isDay(s)
{   if (isEmpty(s)) 
       if (isDay.arguments.length == 1) return defaultEmptyOK;
       else return (isDay.arguments[1] == true);   
    return isIntegerInRange (s, 1, 31);
}


// daysInFebruary (INTEGER year)
// 
// Given integer argument year,
// returns number of days in February of that year.
function daysInFebruary(year)
{   // February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (  ((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0) ) ) ? 29 : 28 );
}


// isDate (STRING year, STRING month, STRING day)
//
// isDate returns true if string arguments year, month, and day 
// form a valid date.
// 
function isDate(year, month, day)
{   // catch invalid years (not 2- or 4-digit) and invalid months and days.
    if (! (isYear(year, false) && isMonth(month, false) && isDay(day, false))) return false;

    // Explicitly change type to integer to make code work in both
    // JavaScript 1.1 and JavaScript 1.2.
    var intYear = parseInt(year);
    var intMonth = parseInt(month);
    var intDay = parseInt(day);

    // catch invalid days, except for February
    if (intDay > daysInMonth[intMonth]) return false; 

    if ((intMonth == 2) && (intDay > daysInFebruary(intYear))) return false;

    return true;
}


// Display prompt string s in status bar.
function prompt(s)
{   window.status = s
}


// Display data entry prompt string s in status bar.
function promptEntry(s)
{   window.status = "Please enter a " + s
}


// Notify user that required field theField is empty.
// String s describes expected contents of theField.value.
// Put focus in theField and return false.
function warnEmpty(theField, s)
{   
    alert(mPrefix + s + mSuffix);
    theField.focus();
    return false;
}


// Notify user that contents of field theField are invalid.
// String s describes expected contents of theField.value.
// Put select theField, pu focus in it, and return false.
function warnInvalid(theField, s)
{   
    alert(s);
    theField.focus();
    theField.select();
    return false;
}


// checkString (TEXTFIELD theField, STRING s, [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is not all whitespace.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkString(theField, s, emptyOK)
{   // Next line is needed on NN3 to avoid "undefined is not a number" error
    // in equality comparison below.
    if (checkString.arguments.length == 2) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (isWhitespace(theField.value)) 
       return warnEmpty (theField, s);
    else return true;
}


// checkStringLength (TEXTFIELD theField, STRING s, INT length)
//
// Check that string theField.value is not too long.
//
function checkStringLength(theField, s, length)
{   if (theField.value.length > length) {
		alert(s + " value is too long, should be " + length + " characters or less.");
		theField.focus();
		return false;
	}
    else return true;
}

// checkStringLengthCustomMessage (TEXTFIELD theField, INT length, STRING msg)
//
// Check that string theField.value is not too long and display a 
// custom error message if it is.
//
function checkStringLengthCustomMessage(theField, length, msg)
{   if (theField.value.length > length) {
                alert(msg);
                theField.focus();
                return false;
        }
    else return true;
}

// checkSelect (SELECT theField, STRING s [, INT index,] [, BOOLEAN emptyOK==false])
//
// Check that select theField was selected.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkSelect(theField, s, index, emptyOK)
{   // Next line is needed on NN3 to avoid "undefined is not a number" error
    // in equality comparison below.
    if (checkSelect.arguments.length == 2) {
		index = -1;
		emptyOK = defaultEmptyOK;
	}
    if (checkSelect.arguments.length == 3) 
		emptyOK = defaultEmptyOK;
    if ((emptyOK == false) && (theField.selectedIndex == index)) {
       return warnEmpty (theField, s);
	}
    else return true;
}


// checkStateCode (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid U.S. state code.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkStateCode(theField, emptyOK)
{   if (checkStateCode.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  theField.value = theField.value.toUpperCase();
       if (!isStateCode(theField.value, false)) 
          return warnInvalid (theField, iStateCode);
       else return true;
    }
}


// takes ZIPString, a string of 5 or 9 digits;
// if 9 digits, inserts separator hyphen
function reformatZIPCode (ZIPString)
{   if (ZIPString.length == 5) return ZIPString;
    else return (reformat (ZIPString, "", 5, "-", 4));
}


// checkZIPCode (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid ZIP code.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkZIPCode(theField, emptyOK)
{   if (checkZIPCode.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    { var normalizedZIP = stripCharsInBag(theField.value, ZIPCodeDelimiters)
      if (!isZIPCode(normalizedZIP, false)) 
         return warnInvalid (theField, iZIPCode);
      else 
      {  // if you don't want to insert a hyphen, comment next line out
         theField.value = reformatZIPCode(normalizedZIP)
         return true;
      }
    }
}


// checkZIPCode2 (TEXTFIELD theField5, TEXTFIELD theField4 [, BOOLEAN emptyOK==false])
//
// Check that string theField5.value is a valid 5 digit ZIP code,
// and the string theField4.value (optionally) contains a valid 4 digit
// ZIP extension
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkZIPCode2(theField5, theField4, emptyOK)
{
    var valid = true;

    if (checkZIPCode2.arguments.length == 2) emptyOK = defaultEmptyOK;

    var empty = isEmpty(theField5.value) && isEmpty(theField4.value);
    if (empty) {
        valid = emptyOK;
    }
    else { 
        // Check the length first 
        if (theField5.value.length != 5 ||
            (!isEmpty(theField4.value) && theField4.value.length != 4)) {
            valid = false;
        } 
        else {
            // Check that all the characters are digits
            if (!isInteger(theField5.value))
                valid = false;
            if (!isEmpty(theField4.value) && !isInteger(theField4.value))
                valid = false;
        }
    }
   
    if (!valid)
        return warnInvalid (theField5, iZIPCode);
    else
        return true;
}


// takes USPhone, a string of 10 digits
// and reformats as (123) 456-789
function reformatUSPhone(USPhone)
{   
	if( USPhone.length == 10){
		return (reformat (USPhone, "(", 3, ") ", 3, "-", 4));
	}
	else {
		var ext = USPhone.length - 10;
		return (reformat (USPhone, "(", 3, ")", 3, "-", 4, " x", ext));
	}	
}


// checkUSPhone (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid US Phone.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkUSPhone(theField, emptyOK)
{   if (checkUSPhone.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  var normalizedPhone = stripCharsInBag(theField.value, phoneNumberDelimiters)
       if (!isUSPhoneNumber(normalizedPhone, false)) 
          return warnInvalid (theField, iUSPhone);
       else 
       {  // if you don't want to reformat as (123) 456-789, comment next line out
          theField.value = reformatUSPhone(normalizedPhone)
          return true;
       }
    }
}

// checkUSPhone2 (TEXTFIELD theField1, TEXTFIELD theField2, TEXTFIELD theField3 [, BOOLEAN emptyOK==false])
//
// Check that string theField1.value is a valid 3 digit area code,
// and the string theField2.value is a valid 3 digit exchange,
// and the string theField3.value is a valid 4 digit number.
//
function checkUSPhone2 (theField1, theField2, theField3, emptyOK)
{
    var valid = true;

    if (checkUSPhone2.arguments.length == 3) emptyOK = defaultEmptyOK;

    // Check the length first 
    var empty = isEmpty(theField1.value) && isEmpty(theField2.value) && isEmpty(theField3.value); 
    if (empty) {
		valid = emptyOK;
    }
    else {
        if (theField1.value.length != 3 || theField2.value.length != 3 || theField3.value.length != 4) {
	        valid = false;
        }
    	else {
		     // Check that all the characters are digits
		    if (!isInteger(theField1.value))
		       valid = false;
		    if (!isInteger(theField2.value))
		       valid = false;
		    if (!isInteger(theField3.value))
		       valid = false;
        }
    }
   
    if (!valid)
        return warnInvalid (theField1, iUSPhone);
    else
        return true;
}


// checkEmail (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid Email.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkEmail(theField, emptyOK)
{   
    var valid = false;
    if (checkEmail.arguments.length == 1) emptyOK = defaultEmptyOK;
    
    var empty = isEmpty(theField.value);
    if (empty) {
        valid = emptyOK;
    }
    else {    
        valid = !isEmail(theField.value, false);
    }

    if (valid)
        return warnInvalid (theField, iEmail);
    else 
        return true;
}


// Check that string theField.value is a valid Year.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkYear(theField, emptyOK)
{   if (checkYear.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isYear(theField.value, false)) 
       return warnInvalid (theField, iYear);
    else return true;
}


// Check that string theField.value is a valid Month.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkMonth(theField, emptyOK)
{   if (checkMonth.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isMonth(theField.value, false)) 
       return warnInvalid (theField, iMonth);
    else return true;
}


// Check that string theField.value is a valid Day.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkDay(theField, emptyOK)
{   if (checkDay.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isDay(theField.value, false)) 
       return warnInvalid (theField, iDay);
    else return true;
}


// checkDate (yearField, monthField, dayField, STRING labelString [, OKtoOmitDay==false])
//
// Check that yearField.value, monthField.value, and dayField.value 
// form a valid date.
//
// If they don't, labelString (the name of the date, like "Birth Date")
// is displayed to tell the user which date field is invalid.
//
// If it is OK for the day field to be empty, set optional argument
// OKtoOmitDay to true.  It defaults to false.
function checkDate(yearField, monthField, dayField, labelString, OKtoOmitDay)
{   // Next line is needed on NN3 to avoid "undefined is not a number" error
    // in equality comparison below.
    if (checkDate.arguments.length == 4) OKtoOmitDay = false;
    if (!isYear(yearField.value)) return warnInvalid (yearField, iYear);
    if (!isMonth(monthField.value)) return warnInvalid (monthField, iMonth);
    if ( (OKtoOmitDay == true) && isEmpty(dayField.value) ) return true;
    else if (!isDay(dayField.value)) 
       return warnInvalid (dayField, iDay);
    if (isDate (yearField.value, monthField.value, dayField.value))
       return true;
    alert (iDatePrefix + labelString + iDateSuffix)
    return false
}


// Get checked value from radio button.
function getRadioButtonValue(radio)
{ var value = null;  
  for (var i = 0; i < radio.length; i++)
    {   
      if (radio[i].checked) { 
        value = radio[i].value;
        break ;
        }
    }
  return value;
}


// Toggle checkbox value
function toggleCheckbox(cbox) 
{
	box = eval(cbox);
	box.checked = !box.checked;
}


function checkGSAContract(theField, emptyOK) 
{
	var pattern = /GS[-]\d{2}\w[-]\d{4}\w/;
    var contract = theField.value;
    
    if (checkGSAContract.arguments.length == 1) emptyOK = defaultEmptyOK;    
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
        
	var result = contract.match(pattern);
	if (result == null){
		alert("Invalid GSA Contract Number. The schedule number should have the form: GS-nnx-nnnnx");
        theField.focus();
		return false;
	} else {
        return true;
    }
}


function checkURLProtocol (p) {

	var prot=p.toLowerCase();
	if ((prot != "http") && (prot != "https") && (prot != "ftp")) return false;
	return true;
}


function checkURLHost(h) {
 var hostFormat=/([\w]+)\.([\w]+)/;
 var result = h.match(hostFormat);
 if (result != null) {
 	if ((result[1] == null) || (result[2] == null)) return false;
 	return true;
 } else {
 	return false;
 }

}


function checkURL(urlctrl, name) 
{
	var url = urlctrl.value;
	var urlFormat = /(\w+):\/\/([\w.]+)/;
	var result = url.match(urlFormat);
	if (result != null) {
		var status =checkURLProtocol(result[1]);
		if (!status) {
			alert("Invalid " + name + ".  Invalid Protocol: must be one of: HTTP, HTTPS, FTP");
			urlctrl.focus();
			return false;
		}

		status = checkURLHost (result[2]);
		if (!status) {
			alert("Invalid " + name + ".  Invalid Host format.");
			urlctrl.focus();
			return false;
		}
		return true;
	} 
	else {
		urlFormat = /([\w.]+)/;
		result = url.match(urlFormat);
		if (result == null) {
			alert("Invalid " + name + ".");
			urlctrl.focus();
			return false;
		}
		status = checkURLHost (result[1]);
		if (!status) {
			alert("Invalid " + name + ".");
			urlctrl.focus();
			return false;
		} 
		else 
			return true;
	}
}


function checkURL2(url)
{
    if (url.length == 0){
        alert ("Please enter a URL.");
    } else {
		checkURL(url);
    }
}


function formatURL(ctl) 
{
    var url = ctl.value.replace(/\s/g,"");
    
    if (url.length != 0) {
        if ((result=url.match(/^\w+:[\/]*$/)) != null) {
            ctl.value = "";
        } else if (url.match(/^\w+:\/\/[\w.]+/) != null) {
            ctl.value = url;
        } else if ((result=url.match(/^(\w+):\/([\w.]+)/)) != null) {
            ctl.value = result[1] + "://" + result[2];
        } else if ((result=url.match(/^(\w+):([\w.]+)/)) != null) {
            ctl.value = result[1] + "://" + result[2];
        } else {
            ctl.value = "http://" + url;
        }
    }
    return true;
}


function checkWebsiteProtocol (p) {

	var prot=p.toLowerCase();
	if ((prot != "http") && (prot != "https")) return false;
	return true;
}


function checkWebsite(urlctrl, name) 
{
    // requires protocol://a.b.c or a.b.c to be valid
	var url = urlctrl.value;
	var urlFormat = /(\w+):\/\/([\w.]+)/;
	var result = url.match(urlFormat);
	if (result != null) {
		var status = checkWebsiteProtocol(result[1]);
		if (!status) {
			alert("Invalid " + name + ".  Invalid Protocol: must be one of: HTTP, HTTPS");
			urlctrl.focus();
			return false;
		}

		urlFormat = /\w+\.\w+\.\w+/;
	    result = url.match(result[2]);
	    if (result == null) {
			alert("Invalid " + name + ".");
			urlctrl.focus();
			return false;
		}
    }
    else {
		urlFormat = /\w+\.\w+\.\w+/;
		result = url.match(urlFormat);
		if (result == null) {
			alert("Invalid Website" + name + ".");
			urlctrl.focus();
			return false;
		}
	} 

	return true;
}


function checkTwoPasswords(theField1, theField2) 
{
    valid = true;
	if (theField1.value.length==0 || theField2.value.length==0) {
        alert("You have to supply a valid password in both fields");
        theField1.focus();
        valid = false;
    } else if (!checkPassword(theField1.value)) {
		alert("Password is invalid.  Passwords must be 8 - 12 characters in length and must contain a mix of alpha and numeric characters.");
		theField1.focus();
		valid = false;
	}
	else if (theField1.value != theField2.value) {
        alert("Passwords do not match");
        theField1.focus();
        valid = false;
    }
	return valid;
}


function checkPassword(pwd) 
{
	var formatOther = /^\w+$/;		//checks that no non-alphanumeric chars are included
	var formatNumber = /\d/;		// checks that there is at least one digit
	var formatAlpha = /[A-Za-z]/;	// checks that there is at least one alpha
	if (pwd.match(formatOther) != null &&
		pwd.match(formatNumber) != null &&
		pwd.match(formatAlpha) != null &&
		pwd.length >= 8)
		return true;
	else 
		return false;
}


function processKeyUp(field1, length, field2) 
{
	var value = field1.value;
	if (value.length == length)
		field2.focus();
}



function checkNumberSelected(selectEl, s, maxAllowed, index, emptyOK, mustSelectMultiple) {
   // initialize the counter
   var counter = 0;
   if(checkNumberSelected.arguments.length == 3) {
     emptyOK = defaultEmptyOK;
     index = -1;
    }
   if (checkNumberSelected.arguments.length < 6) {
     mustSelectMultiple = false;
   }
   // Loop through the select box to see how many are selected;
   for (i=0; i< selectEl.length; i++){
      // If an element is selected, increment the counter
      if (selectEl[i].selected == true){
        if (i != index) {
          // the index is the default value so this cannot be a selection and should not be counted
          counter++;
        }
      }
   }
   // If the counter is greater than maxAllowed, display an alert message.
   if (maxAllowed != -1) {
     if (counter > maxAllowed){
       alert("You have selected more than " + maxAllowed + " " + s + "s - " + maxAllowed + " is the maximum number allowed.");
       selectEl.focus();
       return false;
     }
   }

   if (!emptyOK) {
     if (counter == 0) {
       alert("You must make a selection from " + s);
       selectEl.focus;
       return false;
     }
   }

   if (mustSelectMultiple && !emptyOK) {
     if (counter == 1) {
       alert("You have only selected 1 " + s +". Based on your selections you are required to select multiple " + s +"s.");
       selectEl.focus;
       return false;
     }
   }

   return true;
}