Javascript : how to detect form elements that have changed.

Well if all of the form fields are text fields then you can loop through and check to see if the value of the field is not equal to the default (if the field is empty it would be like this):

if(formfield.value != "") {
//do stuff
}

This can also work with almost every other type of form field by just knowing the default option and checking accordingly. (In the case of a checkbox you could see if it was checked it it defaults to unchecked)

Just using onChange attribute of the input field, every input field has onChange event, just add an event listener to each input field, the following will upper case the input (if I not misunderstand your provided code):
  <script type="text/javascript">
   function upperMe(el){
   alert(el);
     if ((el.tagName.toLowerCase() == "input") && (el.type.toLowerCase() == 'text')){
         // Make sure we get the desired element <input type="text">
         el.value = el.value.toUpperCase();
     }
   }
</script>
<form>
<input type="text" onchange="upperMe(this)">
...
</form>

So you want to only save the changed fields.
reading your code, I assume you have a bunch of fields all called landingpages, some hidden
I also assume you have for values entered some fields called vanity_something where the user can enter something

I think I would code it like this (assuming the above is correct - next time post more code, please):

for (var i=0; i < form.landingpages.length; i++){                        
  //do not process the hidden field
  if (form.elements['landingpages'][x].type == 'hidden') continue;                  
  var page = form.elements['landingpages'][i].value;
// keep a track of vanities to be created
  var vanity = form.elements["vanity_" +page].value;
  if (vanity.length > 0 && vanity !=form.elements["vanity_" +page].defaultValue)  {
    aVanitiesToAdd.push(vanity.toUpperCase());
  }                                        
}

Michel

Thanks Michel.
Here is the full code I think :)
      var aVanityNames = new Array(#UCase(QuotedValueList(rsVanities.vcVanityName))#);
            var aReservedVanityNames = new Array(#UCase(QuotedValueList(Session.stCampaign.stSettings.rsReservedVanities.Name))#);

            for (var x=0; x < form.landingpages.length; x++){                                                                  
                  //do not process the hidden field
                  if (form.elements['landingpages'][x].type != 'hidden') {                  
                        // keep a track of vanities to be created
                        currentVanity = eval("form.vanity_" + form.elements['landingpages'][x].value + ".value.toUpperCase()");                                    
                        if (currentVanity.length > 0) {
                              aVanitiesToAdd.push(currentVanity);
                        }                                                      
      
                        // Check for illegal characters in the vanity name
                        if (currentVanity.match(/[^A-Za-z0-9]/) != null) {
                              dVanityNameError = 1;                        
                              vanityErrorMessage += '* The ' + currentVanity + ' Vanity Name contains illegal characters' + '\n';                                                            
                        }
                        
                        // check vanity does not already exist in db
                        for (var i=0; i<aVanityNames.length; i++) {
                              if ( currentVanity == aVanityNames[i]) {
                                    dVanityNameError = 1;
                                    vanityErrorMessage += '* The ' + currentVanity + ' Vanity Name is already in use' + '\n';
                                    break;
                              }
                        }                                                                  
                  //do not process the hidden field
                  if (form.elements['landingpages'][x].type != 'hidden') {                  
                        // keep a track of vanities to be created
                        currentVanity = eval("form.vanity_" + form.elements['landingpages'][x].value + ".value.toUpperCase()");                                    
                        if (currentVanity.length > 0) {
                              aVanitiesToAdd.push(currentVanity);
                        }                                                      
      
                        // Check for illegal characters in the vanity name
                        if (currentVanity.match(/[^A-Za-z0-9]/) != null) {
                              dVanityNameError = 1;                        
                              vanityErrorMessage += '* The ' + currentVanity + ' Vanity Name contains illegal characters' + '\n';                                                            
                        }
                        
                        // check vanity does not already exist in db
                        for (var i=0; i<aVanityNames.length; i++) {
                              if ( currentVanity == aVanityNames[i]) {
                                    dVanityNameError = 1;
                                    vanityErrorMessage += '* The ' + currentVanity + ' Vanity Name is already in use' + '\n';
                                    break;
                              }
                        }

Actually I was looking for the html of the form
Is the # thingy Cold fusion or something?

And I see the script twice...

Forced accept.

Computer101
EE Admin