public void AddProductToCart(System.Web.HttpRequest req, System.Web.SessionState.HttpSessionState session) { var productId = long.Parse(req.Params["productId"]); var numberOfItems = int.Parse(req.Params["items"]); var product = productCatalog.GetProductById(productId); var items = (Dictionary <Product, int>)session["cart"]; items[product] = numberOfItems; }