private void DisplayRegister()
        {
            Console.Clear();

            User user = new User();

            Console.WriteLine("Enter username: "******"Enter password: "******"Enter password again: ");
            user.ConfirmPassword = Console.ReadLine();
            Console.WriteLine("Enter email: ");
            user.Email = Console.ReadLine();
            Console.WriteLine("Enter first name: ");
            user.FirstName = Console.ReadLine();
            Console.WriteLine("Enter last name: ");
            user.LastName = Console.ReadLine();

            try
            {
                _vm.RegisterUser(user);
                Console.WriteLine($"Welcome {_vm.CurrentUser.FirstName} {_vm.CurrentUser.LastName}");
                Console.ReadKey();
                VendingMenu();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.ReadKey();
            }
        }
        public ActionResult Register(RegisterViewModel model)
        {
            ActionResult result = null;

            try
            {
                if (!ModelState.IsValid)
                {
                    throw new Exception();
                }

                try
                {
                    User userModel = new User();
                    userModel.ConfirmPassword = model.ConfirmPassword;
                    userModel.Password = model.Password;
                    userModel.FirstName = model.FirstName;
                    userModel.LastName = model.LastName;
                    userModel.Username = model.Username;
                    userModel.Email = model.Email;
                    _vm.RegisterUser(userModel);
                }
                catch (UserExistsException)
                {
                    ModelState.AddModelError("invalid-user", "The username is already taken.");
                    throw;
                }

                result = RedirectToAction("Index", "Vending");
            }
            catch (Exception)
            {
                result = View("Register");
            }

            return result;
        }