public ActionResult Login(LoginAuthenticationViewModel viewModel)
        {
            User user = null;

            if (ModelState.IsValid)
            {
                user = db.Users.FirstOrDefault(u => u.Username.Equals(viewModel.Username) && u.Password.Equals(viewModel.Password));
                if (user != null)
                {
                    FormsAuthentication.SetAuthCookie(user.Username, false);
                    return(RedirectToAction("Index", "Home"));
                }
                ModelState.AddModelError("", "Wrong username and/or password");
            }
            return(View(user));
        }
        // GET: Login
        public ActionResult Login()
        {
            LoginAuthenticationViewModel viewModel = new LoginAuthenticationViewModel();

            return(View(viewModel));
        }