function prepFormFields() {
  var htmlElements = Array('select', 'input', 'textarea');
  var htmlTempArray;
  for (var i = 0; i < htmlElements.length; i++) {
   htmlTempArray = document.getElementsByTagName(htmlElements[i]);
   for (var j = 0; j < htmlTempArray.length; j++) {
    htmlTempArray[j].onmouseover = htmlTempArray[j].onfocus = function() {
     this.className = "selected";
     }
    htmlTempArray[j].onmouseout = htmlTempArray[j].onblur = function() {
     this.className = "";
    }
   }
  }
 }

function isNotEmpty(elem) {
  var str = elem.value;
  if(str == null || str.length == 0) 
   return false;
  else 
   return true;
 }
 
 // THIS FUNCTION PERFORMS VALIDATION BASED ON A SET OF CUSTOM HTML ATTRIBUTES
 function validate(form) {
  var attrVal, attrReg, attrEq, attrFail, strTemp;

  for (var i = 0; i < form.length; i++) {
   attrVal = form[i].getAttribute("validate");
   
   switch (attrVal) {
    case 'required' :
    if (!isNotEmpty(form[i])) {
     attrFail = form[i].getAttribute("failure");
     
     if (attrFail)
      alert(attrFail);
     else     
      alert('You must complete all required form fields.');
     form[i].focus();
     return false;
    }
    break;
    
    case 'regex' :
    attrReg = form[i].getAttribute("regex");
    if (attrReg != null && attrReg.length != 0) {
     var regex = new RegExp(attrReg);
     strTemp = form[i].value;
     if (!strTemp.match(regex)) {
      attrFail = form[i].getAttribute("failure");

      if (attrFail)
       alert(attrFail);
      else
       alert('Invalid data format at field "' + form[i].name + '".');
      form[i].focus();
      return false;
     }
    }
    break;
    
    case 'equals' :
    attrEq = form[i].getAttribute("equals");
    var objEq = document.getElementById(attrEq);
    if (objEq) {
     if (form[i].value != objEq.value) {
      attrFail = form[i].getAttribute("failure");
      
      if (attrFail)
       alert(attrFail);
      else
       alert('Form fields do not match');
      
      form[i].focus();
      return false;
     }
    }
    break;
   }
   
  }
  
  return true;
 }