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));
        }