Form validation not working

Hi!

I'm trying to validate a form. In my jquery file I'm using this code:

(function() { 'use strict'; window.addEventListener('load', function() { // Fetch all the forms we want to apply custom Bootstrap validation styles to var forms = document.getElementsByClassName('needs-validation'); // Loop over them and prevent submission var validation = Array.prototype.filter.call(forms, function(form) { form.addEventListener('submit', function(event) { if (form.checkValidity() === false) { event.preventDefault(); event.stopPropagation(); } form.classList.add('was-validated'); }, false); }); }, false); })();

The form is submitting instead it's not valid. The invalid-feedback errors appers but then the browser submits form.

I would like to know how to call an Ajax to php function, and use it only with one form insted of a loop with all forms in the page.

thanks!