public ActionResult Registration(RegistrationViewModel registrationViewModel) { string messageRegistration = string.Empty; if (ModelState.IsValid) { if (!CardsService.CardExists(registrationViewModel.CardID)) { ClientsService.CreateClient(registrationViewModel.ConvertToClient()); TempData["statusRegistration"] = true; return(RedirectToAction("Login")); } else { ModelState.AddModelError("", "Card already exists"); } } else { ModelState.AddModelError("", "Something wrong"); } ViewBag.Message = messageRegistration; return(View(registrationViewModel)); }