or
<telerik:RadTreeView ID="treeSubBooks" runat="server" Skin="WebBlue" AllowNodeEditing="false" EnableDragAndDrop="false" OnNodeClick="tree_NodeClick" Width="240px"> </telerik:RadTreeView> <telerik:RadToolTipManager ID="rttmSubBooks" Height="300px" Width="250px" HideEvent="ManualClose" RelativeTo="Element" Position="MiddleLeft" runat="server" ShowDelay="500" Skin="Telerik" EnableShadow="true" Animation="Fade" OnAjaxUpdate="rttmSubBooks_AjaxUpdate"> </telerik:RadToolTipManager>protected void rttmSubBooks_AjaxUpdate(object sender, ToolTipUpdateEventArgs e) { Control ctrl = LoadControl("~/UserControls/ucTooltipTreeviewBook.ascx"); e.UpdatePanel.ContentTemplateContainer.Controls.Add(ctrl); var iuser = (IUserControl)ctrl; iuser.Parameter = e.Value; var action = (ITooltipTreeviewAction)ctrl; action.Action += tooltip_action; } private void tooltip_action(object sender, TooltipTreeviewEventArgs e) { buildSubBooks(e.Action, e.BookName); }<telerik:GridDropDownColumn UniqueName="ISHUR" DataField="ISHUR" HeaderText="MyIshur" DropDownControlType="DropDownList" DataSourceID="objdsIshur" ListTextField="Text" ListValueField="Key"/>