Form validation - one function

formvalidation.js

// put 'req' on the elements of any required input fields. Don't use the 'required' attribute, otherwise the default action
// will trigger.

    function onFormSubmit(form) {
        var isValid = true;
        Array.prototype.forEach.call(form.elements, function (e) {
            if ((e.value.length == 0 || ! /\S/g.test(e.value)) && e.getAttribute('req') !== null && e.getAttribute('req') !== undefined) {
                isValid = false;
                e.value = "";
                if (e.getAttribute('req') == "") {
                    var ph = e.getAttribute('placeholder');
                    e.setAttribute('placeholder', ph + " (חובה)");
                    e.setAttribute('req', 'marked');
                }
            }
        });

        if (!isValid) return false;

        var email = form.elements['youremail'].value;
        if (email.indexOf('@')<0 || email.indexOf('.')<0) {
            alert("אנא הכנס כתובת דואל תקנית");
            form.elements['youremail'].focus();
            return false;
        }
        if (/[^\d\+\-]/g.test(form.elements['yourphone'].value)) {
            alert("אנא הכנס מספר טלפון תקני");
            form.elements['yourphone'].focus();
            return false;
        }

        // Do Submit here
    }