protected void LinkButtonbuyClick(object sender, EventArgs e) { LinkButton btn = (LinkButton)sender; if (!Basket.IsUserExist(Session["iduser"].ToString())) { Basket.AddUser(Session["iduser"].ToString()); } try { Basket.AddUserWare(Session["iduser"].ToString(), btn.CommandArgument); ShowMessage("Ware added to basket"); } catch (ArgumentOutOfRangeException) { ShowMessage("you have already bought this product"); btn.Visible = false; } btn.Visible = false; }