Плагин валидации jQuery
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.19.2/jquery.validate.min.js"></script>
Healthy Hawk
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.19.2/jquery.validate.min.js"></script>function submitFunction(event){
event.preventDefault();
}
$("#form_id").submit(submitFunction);