public ActionResult Login(LoginModel loginModel)
        {
            USER user = new USER();
            AuthorizeDemoEntities db = new AuthorizeDemoEntities();

            user = db.USERS.FirstOrDefault(us => us.UserName.Equals(loginModel.UserName) && us.Password.Equals(loginModel.Password));

            if (user != null)
            {
                FormsAuthentication.SetAuthCookie(user.UserName, false);
                Session["UserName"] = user.UserName;
                return(RedirectToAction("List", "Product"));
            }
            return(View());
        }