protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { ChangeShop.Visible = false; Products.Visible = false; searchPanel.Visible = false; //set data source productOrder.DataSource = OrderByArr; //// Bind the data to the control. productOrder.DataBind(); // Set the default selected item, if desired. productOrder.SelectedIndex = 0; //set data source List <BlShop> shops = BLFlyPack.BlShop.GetShops(); shops.Add(new BlShop("-1", "all products")); Shops.DataSource = shops; Shops.DataTextField = "ShopName"; Shops.DataValueField = "ID"; // Bind the data to the control. Shops.DataBind(); foreach (System.Web.UI.WebControls.ListItem Item in Shops.Items) { Item.Attributes["OnClientClick"] = "ShopDropDownListB_OnClick"; } // Set the default selected item, if desired. Shops.SelectedIndex = shops.Count - 1; Session["products"] = null; //Products.ProductsCollections = products; List <BLProduct> productsCart = (List <BLProduct>)Session["productsCart"]; if (productsCart == null || productsCart.Count == 0) { MSG.Text = ""; return; } } }