public ActionResult Index()
        {
            var cart = ShoppingCartService.GetCart(HttpContext);

            var viewModel = new ShoppingCartViewModel
            {
                CartItems = cart.GetCartItems(),
                CartTotal = cart.GetTotal()
            };

            return View(viewModel);
        }
        public ActionResult RemoveFromModule(int id)
        {
            var cart = ShoppingCartService.GetCart(HttpContext);

            cart.RemoveFromCart(id);

            var viewModel = new ShoppingCartViewModel
            {
                CartItems = cart.GetCartItems(),
                CartTotal = cart.GetTotal()
            };

            return View("Module",viewModel);
        }