public ActionResult Checkout(CheckoutViewModel model) { if (!ModelState.IsValid) { return View(model); } var cart = new ShoppingCartService(HttpContext); var result = cart.Checkout(model); if (result.Message=="Pass") { TempData["transactionId"] = result.TransactionId; cart.ClearCart(HttpContext); return RedirectToAction("Complete"); } ModelState.AddModelError(string.Empty, result.Message); return View(model); }