public void AddOnCart(Cart cart) { if (Session["Cart"] == null) { List <Cart> carts = new List <Cart>(); Cart cartModel = new Cart(); cartModel.ItemId = cart.ItemId; cartModel.Quantity = cart.Quantity; cartModel.CompanyId = cart.CompanyId; cartModel.Discount = cart.Discount; decimal priceWithDiscount = stockOutManager.ComputePriceWithDecimal(cart.Discount, cart.ItemId, cart.Quantity); cartModel.Price = priceWithDiscount; carts.Add(cartModel); Session["Cart"] = carts; } else { if (IsAlreadyExists(cart.ItemId)) { UpdateQuantity(cart.ItemId, cart.Quantity); } else { List <Cart> carts = Session["Cart"] as List <Cart>; Cart cartModel = new Cart(); cartModel.ItemId = cart.ItemId; cartModel.Quantity = cart.Quantity; cartModel.CompanyId = cart.CompanyId; cartModel.Discount = cart.Discount; decimal priceWithDiscount = stockOutManager.ComputePriceWithDecimal(cart.Discount, cart.ItemId, cart.Quantity); cartModel.Price = priceWithDiscount; carts.Add(cartModel); Session["Cart"] = carts; } } }