public ActionResult UserAgreement(Guid id /* orderItemId */)
        {
            if (id == Guid.Empty)
                return HttpNotFound();

            var orderItem = _orderService.GetOrderItemByGuid(id);
            if (orderItem == null)
                return RedirectToHomePageWithError("Guid");

            var product = orderItem.Product;
            if (product == null || !product.HasUserAgreement)
                return RedirectToHomePageWithError("Product");

            var model = new UserAgreementModel();
            model.UserAgreementText = product.UserAgreementText;
            model.OrderItemGuid = id;

            return View(model);
        }
        public ActionResult UserAgreement(Guid orderItemId)
        {
            var orderItem = _orderService.GetOrderItemByGuid(orderItemId);
            if (orderItem == null)
                return RedirectToRoute("HomePage");

            var product = orderItem.Product;
            if (product == null || !product.HasUserAgreement)
                return RedirectToRoute("HomePage");

            var model = new UserAgreementModel();
            model.UserAgreementText = product.UserAgreementText;
            model.OrderItemGuid = orderItemId;
            
            return View(model);
        }