public ActionResult Index(RegisterViewModel model) { if (string.IsNullOrWhiteSpace(model.Login) || string.IsNullOrWhiteSpace(model.Password) || string.IsNullOrWhiteSpace(model.PasswordRepeat)) { return(View(RegisterViewModel.ErrorMessage("You should fill all the fields"))); } var login = model.Login.Trim(); if (loginRegex.IsMatch(login)) { return(View(RegisterViewModel.ErrorMessage("User Name may contain only letters, digits and white spaces"))); } var password = model.Password.Trim(); var passwordRepeat = model.PasswordRepeat.Trim(); if (!password.Equals(passwordRepeat)) { return(View(RegisterViewModel.ErrorMessage("The passwords are not same"))); } if (CheckLogin(login)) { return(View(RegisterViewModel.ErrorMessage("A user with the same login already exists"))); } var registerResult = CreateUser(login, password); return (View(registerResult.Item1 ? RegisterViewModel.SuccessMessage("The registration has been performed with success") : RegisterViewModel.ErrorMessage(registerResult.Item2))); }