or
<telerik:RadComboBox ID="RadComboBox1" runat="server" Width="350px" EnableLoadOnDemand="True" onitemsrequested="RadComboBox1_ItemsRequested" onselectedindexchanged="RadComboBox1_SelectedIndexChanged" ExpandDirection="Up" AutoPostBack="True" AppendDataBoundItems="True"></telerik:RadComboBox>protected void RadComboBox1_ItemsRequested(object o, Telerik.Web.UI.RadComboBoxItemsRequestedEventArgs e) { Telerik.Web.UI.RadComboBox combo = (Telerik.Web.UI.RadComboBox)o; SqlDataAdapter da = new SqlDataAdapter("SELECT iladi from iller WHERE iladi LIKE '" + e.Text + "%'", MyConnection); DataTable dt = new DataTable(); da.Fill(dt); foreach (DataRow row in dt.Rows) { Telerik.Web.UI.RadComboBoxItem item = new Telerik.Web.UI.RadComboBoxItem(row["iladi"].ToString()); combo.Items.Add(item); } }protected void RadComboBox1_SelectedIndexChanged(object sender, Telerik.Web.UI.RadComboBoxSelectedIndexChangedEventArgs e) { //Label1.Text = RadComboBox1.SelectedItem.ToString(); Label1.Text = RadComboBox1.SelectedValue.ToString(); }