Can't add event listener at page load reliably

Question

I can't seem to add these event listeners at page load reliably. Some of the listeners work from the beginning, but others only work after a few clicks. What might be wrong? Could the problem be that I'm mixing native JS with jQuery?

<script>
$(document).ready(function() {

function resetValidation() {
  jQuery('#contact-form').validate().resetForm();
};

function resetFormFields() {
  document.getElementById('contact-form').reset();
};

function removeValidationClasses() {
  jQuery('.control-group').removeClass('success').removeClass('error');
};

function changeHeaderToAdd() {
  document.getElementById('contactModalLabel').innerText = 'Add Contact';
};

function changeHeaderToUpdate() {
  document.getElementById('contactModalLabel').innerText = 'Update Contact';
};

function clearContactId() {
  document.getElementById('contactId').value = '';
};

  var ab = document.getElementById('addContactBtn');
  if (ab.addEventListener) {
    ab.addEventListener('click', resetValidation, false);
    ab.addEventListener('click', resetFormFields, false);
    ab.addEventListener('click', removeValidationClasses, false);
    ab.addEventListener('click', changeHeaderToAdd, false);
    ab.addEventListener('click', clearContactId, false);
  } else {
    ab.attachEvent('onclick', resetValidation);
    ab.attachEvent('onclick', resetFormFields);
    ab.attachEvent('onclick', removeValidationClasses);
    ab.attachEvent('onclick', changeHeaderToAdd);
    ab.attachEvent('onclick', clearContactId);
  };
  var ub = document.getElementById('updateContactBtn');
  if (ub.addEventListener) {
    ub.addEventListener('click', resetValidation, false);
    ub.addEventListener('click', resetFormFields, false);
    ub.addEventListener('click', removeValidationClasses, false);
    ub.addEventListener('click', changeHeaderToUpdate, false);
  } else {
    ub.attachEvent('onclick', resetValidation);
    ub.attachEvent('onclick', resetFormFields);
    ub.attachEvent('onclick', removeValidationClasses);
    ub.attachEvent('onclick', changeHeaderToUpdate);
  };
});
</script>

Answer 1

Solved!

The JS was fine. However, since #updateContactBtn was created dynamically (one for each contact on the page), the problem was caused by the presence of nonunique id's. Only the first instance of #updateContactBtn worked.

I changed #updateContactBtn to .updateContactBtn.