public ActionResult RegisterForm(RegisterControllerRegisterVM model)
 {
     TryUpdateModel(model);
     if (ModelState.IsValid)
     {
         User user = new User();
         user.FirstName = model.FirstName;
         user.LastName = model.LastName;
         user.UserName = model.UserName;
         user.Password = model.Password;
         userRepository.Save(user);
         Session["User"] = user;
         AuthenticationService.AuthenticateUser(user.UserName,user.Password);
         return RedirectToAction("ListContact","Contact");
     }
     return View(model);
 }
 public static bool AuthenticateUser(string username, string password)
 {
     UserRepository userRepository = new UserRepository();
     LoggedUser = userRepository.GetAll(filter: u => u.UserName == username && u.Password == password).FirstOrDefault();
     return LoggedUser != null;
 }