public ActionResult Index(user u)
        {
            envanterDBEntities db = new envanterDBEntities();
            var data = db.SP_getLoginDetails(u.user_userName, u.userPassword);

            foreach (var item in data)
            {
                if (item.Username == u.user_userName && item.Password == u.userPassword)
                {
                    Session["Name"] = u.user_userName;
                    return(RedirectToAction("Main"));
                }
            }
            return(View());
        }