Prevent "AJAX HTTP request terminated" error on early form submit
This might help you.

Drupal.behaviors.merchant = {
  attach: function(context, settings) {
    jQuery('form.node-form')
      .ajaxStart( function() {
          jQuery(this).submit(function() {
            return false;
          });
        })
       .ajaxStop( function() {
          jQuery(this).unbind('submit');
          jQuery(this).submit(function() {
            return true;
          });
        });
  }
}