How can I add Live Validation to the Landing Page?

Hello everyone,

In Eloqua forms, there is code for Live Validation already, but unfortunately we cannot edit the form code. I want to add my own code to the live validation section for other fields, how can I do that? I tried adding it to the JS Editor on the landing page, but I have no luck. We need to use Eloqua forms instead of external forms because we need to sync the data between Eloqua and CRM.

Here is my code for "at least one checkbox must be checked." The following code works great if I put it in the form code.

function isChecked(){

            var selectd = 0;

            if(document.forms['Elq_NewsletterSignupRepost'].NewsletterEdition_bus.checked)

            selectd++;

  if(document.forms['Elq_NewsletterSignupRepost'].NewsletterEdition_dev.checked)

            selectd++;

            return (selectd > 0)? true : false;

            }

  var field7 = new LiveValidation("field7", {onlyOnSubmit: true, insertAfterWhatNode: "errMsg"});

  field7.add(Validate.Custom, {against: function(value){return isChecked(value)}, failureMessage: "Please select at least one option."});

  var field8 = new LiveValidation("field8", {onlyOnSubmit: true, insertAfterWhatNode: "errMsg"});

  field8.add(Validate.Custom, {against: function(value){return isChecked(value)}, failureMessage: "Please select at least one option."});

Anybody can give me some tips? I will be very appreciated.

Thanks,

Edison