onclick without postback login form in mvc4

<script src="jquery-1.4.1.min.js" type="text/javascript"></script>
<script language="javascript">
    function ValidateUser() {
        var userid = $("#<%=txtuserid.ClientID %>").attr('value');
        var password = $("#<%=txtpassword.ClientID %>").attr('value');
        $("#btnSubmit").attr({ 'value': 'Please wait...' });
        $.ajax({
            url: "Home/Index",
            type: "POST",
            cache: false,
            success: function (html) {
                if (html == "1") {
                    alert("Successfull login.");
                } else {
                    alert("Wrong User Id and Password.");
                }

                $("#btnSubmit").attr({ 'value': 'Submit' });
                return false;
            }
        });
    }
</script>

[HttpPost]
      [ValidateAntiForgeryToken]
       public ActionResult Index(LoginMVC u)
       {

           if (ModelState.IsValid) // this is check validity
           {
               using (LoginAndSignUpEntities dc = new LoginAndSignUpEntities())
               {
                   var v = dc.tbl_Detailstbl.Where(a => a.Email_Id.Equals(u.EmailId) && a.Password.Equals(u.Password)).FirstOrDefault();
                   if (v != null)
                   {
                       Session["LogedUserID"] = v.Email_Id.ToString();
                       Session["LogedUserFullname"] = v.Name.ToString();
                       return RedirectToAction("AfterLogin");
                   }
               }
           }
           return View(u);
       }
      public ActionResult AfterLogin()
      {
          if (Session["LogedUserID"] != null)
          {
              return View();
          }
          else
          {
              return RedirectToAction("Index");
          }
      }