public ActionResult AddProduct(AddProductView view)
        {
            var user =
                db.Users.
                Where(us => us.UserName == User.Identity.Name).
                FirstOrDefault();

            if (ModelState.IsValid)
            {
                var orderDetailTmp =
                    db.OrderDetailTmps.
                    Where(odt => odt.UserName ==
                          User.Identity.Name &&
                          odt.ProductID == view.ProductId).
                    FirstOrDefault();

                if (orderDetailTmp == null)
                {
                    var product =
                        db.Products.Find(view.ProductId);

                    orderDetailTmp = new OrderDetailTmp
                    {
                        Description = product.Description,
                        Price       = product.Price,
                        ProductID   = product.ProductID,
                        Quantity    = view.Quantity,
                        TaxRate     = product.Tax.Rate,
                        UserName    = User.Identity.Name,
                    };

                    db.OrderDetailTmps.
                    Add(orderDetailTmp);
                }
                else
                {
                    orderDetailTmp.Quantity += view.Quantity;

                    db.Entry(orderDetailTmp).State =
                        EntityState.Modified;
                }

                db.SaveChanges();

                return(RedirectToAction("Create"));
            }

            ViewBag.ProductId =
                new SelectList(
                    ComboBoxHelpers.
                    GetProducts(
                        user.CompanyId),
                    "ProductID",
                    "Description");

            return(PartialView(view));
        }
        // GET: AddProducts/Create
        public ActionResult AddProduct()
        {
            var user =
                db.Users.
                Where(us => us.UserName == User.Identity.Name).
                FirstOrDefault();

            ViewBag.ProductId =
                new SelectList(
                    ComboBoxHelpers.
                    GetProducts(
                        user.CompanyId),
                    "ProductID",
                    "Description");

            return(PartialView());
        }