Working with Ajax toolkit

1. find AjaxControlToolkit.dll. and place it in your bin folder

2. add the following tag in aspx page

< % @ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajax" % >

3. try the following code

< asp: Panel ID="pnlShowXMLElements" runat="server" CssClass="XMLPopupModalBG" ScrollBars="Vertical" >
< table >
< tr >
< td align="center" style="width:600px">

< /td>
< /tr>
< tr>
< td>

< /td>
< /tr>
< tr id="tr1">
< td>
AutoGenerateDataBindings="true"
OnSelectedNodeChanged="treeSource_SelectionChanged" />
< /td>
< /tr>
< /table>
< /asp:Panel>

< ajax: ModalPopupExtender ID="modalpopup" runat="server" DropShadow="true"
CancelControlID="btnCancelPopup"
TargetControlID="btnOpenTreeView" PopupControlID="pnlShowXMLElements" / >

4. create css class files

5. debug and test