JavaScript Agregar atributo requerido a la entrada
element.setAttribute("required", ""); //turns required on
element.required = true; //turns required on through reflected attribute
jQuery(element).attr('required', ''); //turns required on
$("#elementId").attr('required', ''); //turns required on
element.removeAttribute("required"); //turns required off
element.required = false; //turns required off through reflected attribute
jQuery(element).removeAttr('required'); //turns required off
$("#elementId").removeAttr('required'); //turns required off
if (edName.hasAttribute("required")) { } //check if required
if (edName.required) { } //check if required using reflected attribute
Prasanth PPS