public ActionResult Index([Bind(Include = "CardType, CreditCardNumber")] CreditCard card) { if (ModelState.IsValid) { // Amex if (card.CardType == 1) { card.Result = CardValidator.IsValidAmex(card.CreditCardNumber) ? "Valid" : "Invalid"; } // Discover else if (card.CardType == 2) { card.Result = CardValidator.IsValidDiscover(card.CreditCardNumber) ? "Valid" : "Invalid"; } // Mastercard else if (card.CardType == 3) { card.Result = CardValidator.IsValidMastercard(card.CreditCardNumber) ? "Valid" : "Invalid"; } // Visa else { card.Result = CardValidator.IsValidVisa(card.CreditCardNumber) ? "Valid" : "Invalid"; } } return(View(card)); }