public ActionResult Signup(SignupModel model)
        {
            if (_accountRepository.All().Any(p => p.UserName == model.Username)) {
            return Signup("Er bestaat al een gebruiker met dezelfde naam.");
              }

              if (string.IsNullOrEmpty(model.FullName) || string.IsNullOrEmpty(model.Username) || string.IsNullOrEmpty(model.Email)) {
            return Signup("Vul a.u.b. alle velden in.");
              }

              var account = new Account {
            FullName = model.FullName,
            UserName = model.Username,
            ApiKey = Guid.NewGuid().ToString(),
              };

              account.Password = account.ComputeSaltedHash("123");

              _accountRepository.Save(account);

              return null; //Login(account.Id, "", "~/Account");
        }
 public ActionResult Signup(string errorString)
 {
     var model = new SignupModel();
       ViewBag.ErrorMessage = errorString;
       return View(model);
 }