/* used to handle changes in the location fields of the public search form.
 */ 
function updateSearchLocationFields() {
  if (document.searchForm.regional.checked) {
    enableField(document.searchForm.ff_project_region);
    disableField(document.searchForm.ff_project_state);
    document.searchForm.ff_project_state.selectedIndex = -1;
    disableField(document.searchForm.ff_project_county);
    resetSelectBoxOptions(document.searchForm.ff_project_county, '', 'All'); 
  }
  else if (document.searchForm.ff_project_region.selectedIndex > 0) {
    disableField(document.searchForm.ff_project_state);
    document.searchForm.ff_project_state.selectedIndex = -1;
    disableField(document.searchForm.ff_project_county);
    resetSelectBoxOptions(document.searchForm.ff_project_county, '', 'All'); 
  }
  else if (document.searchForm.ff_project_state.selectedIndex > 0) {
    disableField(document.searchForm.regional);
    disableField(document.searchForm.ff_project_region);
    document.searchForm.ff_project_region.selectedIndex = -1;
    enableField(document.searchForm.ff_project_county);

    // send request for counties
    strRequest="getStateCounties.do" + 
               "?state=" + selectedValue(document.searchForm.ff_project_state) + 
               "&formName=searchForm&formElem=ff_project_county&isSingle=true&destination=forPublicSearch";
    sendRequestStateCounties(strRequest);
  }
  else {
    enableField(document.searchForm.regional);
    enableField(document.searchForm.ff_project_region);
    enableField(document.searchForm.ff_project_state);
    disableField(document.searchForm.ff_project_county);
    resetSelectBoxOptions(document.searchForm.ff_project_county, '', 'All'); 
  }
}