Validate email in a contact form using jQuery/javascript

I'm trying to validate a contact form using jQuery. The name field validates correctly using this function, but no matter what I do I get the error message in the email input whenever I try to send, even with a valid email. At this point I'm truly lost and would really appreciate the help. I'm pretty sure the problem is in the regex in the email if statement (!/^S+@S+.S+$/.test(email.val())), but I just can't figure it out. Here is the function I am using

$(function(){

    var required = ["name", "email", "message"];
    emptyerror = "Please fill out this field";
    emailerror = "Please enter a valid e-mail";
    email = $("#email");
    errornotice = $("#error");

    $("#contactForm").submit(function() {
      for (var i = 0; i < required.length; i++) {

        var inputField = $('#'+required[i]);

        if ((inputField.val() == "") || (inputField.val() == emptyerror)) {
          inputField.addClass("needsfilled");
          inputField.val(emptyerror);
          errornotice.fadeIn(750);
        }
        else {
          inputField.removeClass("needsfilled");
        }
        if (!/^S+@S+.S+$/.test(email.val())) {
            email.addClass("needsfilled");
            email.val(emailerror);
        }
        if ($(":input").hasClass("needsfilled")) {
          return false;
        }
        else {
          errornotice.hide();
          return true;
        }
      }
    });

    $(":input").focus(function() {
      if ($(this).hasClass("needsfilled")) {
        $(this).val("");
        $(this).removeClass("needsfilled");
      }
    })
});

On a side note, I know that there are way better ways to validate not using jQuery/js. But this is for a school project that requires it to be done with javascript, even if it has to be overly simplified.

Thank you