Issue #3265695 by joelpittet: jQuery 1.7+ doesn't use attr for non-attributes

            // ALSO, to deal with Drupal form API form cache, add the form build ID

            // so the background process can update the known fields.

            var form = $('.menu-mlid', parentRow).attr('form')

            // When using jQuery 1.7+, use prop() function instead of the attr()

            // function when not called on an attribute.

            if ($().prop) {

              var form = $('.menu-mlid', parentRow).prop('form');

            }

            else {

              var form = $('.menu-mlid', parentRow).attr('form');

            }

            form_id = $('input[name="form_id"]', form).val();

            form_build_id = $('input[name="form_build_id"]', form).val();

            url += "/" + form_id + "/" + form_build_id