Hello, I am relatively new to Javascript so I'm hoping this is a simple mistake. I building a generic form validation function that is called on the form's onSubmit. The function loops through all the form's child elements, looks for certain classes, and analyzes the contents of the appropriate fields. If it finds something missing or erroneous, it displays the appropriate error message div and returns false, thus preventing the form from being submitted to the php page.

It works well in firefox 3.6.3, but in every other browser I've tested (Safari 4.0.4, Chrome 4.1, IE8) it seems to ignore the onSubmit and jump straight to the php processing page.

HTML CODE:

    <form name='myForm' id='myForm' action='process_form.php' method='post' onSubmit="return validateRequired('myForm')">

   <fieldset class="required radioset">
    <label for='selection1'>
     <input type='radio' name='selection' id='selection1' value='1'/>
     Option 1
    </label>
    <label for='selection2'>
     <input type='radio' name='selection' id='selection2' value='2'/>
     Option 2
    </label>
    <label for='selection3'>
     <input type='radio' name='selection' id='selection3' value='3'/>
     Option 3
    </label>
    <label for='selection4'>
     <input type='radio' name='selection' id='selection4' value='4'/>
     Option 4
    </label>
    <div class='errorBox' style='visibility:hidden'>
     Please make a selection
    </div>
   </fieldset>

   <fieldset class="required checkset">
    <label>
     Choice 1
     <input type='checkbox' name='choices' id='choice1' value='1'/>
    </label>
    <label>
     Choice 2
     <input type='checkbox' name='choices' id='choice2' value='2'/>
    </label>
    <label>
     Choice 3
     <input type='checkbox' name='choices' id='choice3' value='3'/>
    </label>
    <label>
     Choice 4
     <input type='checkbox' name='choices' id='choice4' value='4'/>
    </label>
    <div class='errorBox' style='visibility:hidden'>
     Please choose at least one
    </div>
   </fieldset>


   <fieldset class="required textfield" >
    <label for='textinput1'>
     Required Text:
     <input type='text' name='textinput1' id='textinput1' size='40'/>
    </label>
    <div class='errorBox' style='visibility:hidden'>
     Please enter some text
    </div>
   </fieldset>

   <fieldset class="required email textfield">
    <label for='email'>
     Required Email:
     <input type='text' name='email' id='email' size='40'/>
    </label>
    <div class='errorBox' style='visibility:hidden'>
     The email address you have entered is invalid
    </div>
   </fieldset>


   <div>
    <input type='submit' value='submit'>
    <input type='reset' value='reset'>
   </div>

  </form>

JAVASCRIPT CODE:

    function validateRequired(id){

 var form = document.getElementById(id);
 var errors = 0;
 var returnVal = true;
 for(i = 0; i < form.elements.length; i++){
  var elem = form.elements[i];
  if(hasClass(elem,"required")){

   /*RADIO BUTTON or CHECK BOX SET*/
   if(hasClass(elem,"radioset") || hasClass(elem,"checkset")){
    var inputs = elem.getElementsByTagName("input");
    var check = false;
    for(j = 0; j < inputs.length; j++){
     if(inputs[j].checked){
      check = true;
     }
    }
    if(check == false){
     errors += 1;
     showError(elem);
    } else {
     hideError(elem);
    }
   }

   /*TEXT FIELD*/
   else if(hasClass(elem,"textfield")){
    var input = elem.getElementsByTagName("input");
    if(input[0].value == ""){
     errors += 1;
     showError(elem);
    } else {
     hideError(elem);

     /*EMAIL ADDRESS*/
     if(hasClass(elem,"email")){
      if(isValidEmail(input[0].value) == false){
       errors += 1;
       showError(elem);
      } else {
       hideError(elem);
      }
     }
    }
   }
  }
 }
 if(errors > 0){
  returnVal = false;
 } else {
  returnVal = true;
 }
 return returnVal;}

I know this is a lot of code to look at, but any help would be appreciated. Since it works fine in one browser, Im not sure how to start debugging. Thanks Andrew