private Tuple<bool, string> isPaymentValid(titizOto.Models.titizOtoEntities db) { switch (this.paymentOptionChoose) { case paymentOption.noAnswer: return new Tuple<bool, string>(false, null); case paymentOption.transfer: if (this.transferInfo != null) { var eftItem = db.tbl_bankEft.Where(a => a.bankEftId == this.transferInfo.selectedTransferId).FirstOrDefault(); if (eftItem != null) { return new Tuple<bool, string>(true, null); } } return new Tuple<bool, string>(false, null); case paymentOption.creditCard: if (this.cardInfo != null) { checkoutShared cs = new checkoutShared(db); var cardInfoValidation = cs.isCardInfoValid(this.cardInfo); return cardInfoValidation; } break; } return new Tuple<bool, string>(false, null); }