JavaScript
jQuery(document).ready(function($){ if( $('form').hasClass( 'fluent_form_14' ) ) { var firstName = $('input[name="user_name[first_name]"]'); firstName.on('keyup', function(e){ if ( e.which == 13 ) { e.preventDefault(); } if( firstName.val() === "" || firstName.val() == typeof undefined ) $('.dyn-username').html( 'First Name' ); else $('.dyn-username').html( firstName.val() ); }); } });