public ActionResult Edit(CatalogViewModel catalogviewmodel)
        {
            if (ModelState.IsValid)
            {
                var old = catalogManager.GetCatalog(catalogviewmodel.Code);

                if (old == null)
                {
                    return(HttpNotFound());
                }

                old.Code        = catalogviewmodel.Code;
                old.Description = catalogviewmodel.Description;
                old.Products.Clear();
                old.Products = productManager.GetProducts(x => catalogviewmodel.SelectedProducts.Contains(x.Code));

                catalogManager.UpdateCatalog(old);
                return(RedirectToAction("Index"));
            }
            return(View(catalogviewmodel));
        }