var error_bg_color = '#ffcfcf';
var clear_bg_color = '#ffffff';

function validateEmpty(fld) {
    var error = "";
 
    if (fld.value.length == 0) {
        fld.style.background = error_bg_color; 
        error = field_names[fld.name]+" "+field_empty_msg+".\n"
    } else {
        fld.style.background = clear_bg_color;
    }
    return error;  
} //validateEmpty

function validateEmptyWithOther(fld,fld_other) {
    var error = "";
 
    if (fld.value.length == 0 && fld_other.value.length == 0) {
        fld.style.background = error_bg_color; 
        error = field_names[fld.name]+" "+field_empty_msg+".\n"
    } else {
        fld.style.background = clear_bg_color;
    }
    return error;  
} //validateEmptyWithOther

function trim(s)
{
  return s.replace(/^\s+|\s+$/, '');
} //trim

function validateEmail(fld) {
    var error="";
    var tfld = trim(fld.value);                        // value of field with whitespace trimmed off
    var emailFilter = /^[^@]+@[^@.]+\.[^@]*\w\w$/ ;
    var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/ ;
   
    if (fld.value == "") {
        fld.style.background = error_bg_color; 
        error = email_empty_msg+"\n";
    } else if (!emailFilter.test(tfld)) {              //test email for illegal characters
        fld.style.background = error_bg_color; 
        error = email_not_correct_msg+".\n";
    } else if (fld.value.match(illegalChars)) {
        fld.style.background = error_bg_color; 
        error = email_illegal_char_msg+"\n";
    } else {
        fld.style.background = clear_bg_color; 
    }
    return error;
} //validateEmail

function validateRadioSelect(fld) {
    var error="";
    var radioLength = fld.length;
    var optionChecked = false;
    
    if(radioLength != undefined) {
      for(var i = 0; i < radioLength; i++) {
        optionChecked = optionChecked || fld[i].checked;
      }
      
      if(!optionChecked) {
        error = field_names[fld[1].name]+" "+field_not_checked_msg+"\n";
      }
    }

    return error;
} //validateRadioSelect