I take it you mean you want to create on of these controls:
http://ajax.asp.net/ajaxtoolkit/CollapsiblePanel/CollapsiblePanel.aspx
at runtime.
To do this replace this in the .aspx file:
<asp
anel ID="panelExtenderContainer" runat="server">
<ajaxToolkit:CollapsiblePanelExtender ID="cpp" runat="Server"
TargetControlID="ContentPanel"
ExpandControlID="Panel"
CollapseControlID="Panel"
ScrollContents="False"
Collapsed="False"
ExpandDirection="Vertical"
SuppressPostBack="true"
TextLabelID="TextLabel"
CollapsedText="Collapsed"
ExpandedText="Opened" />
</asp
anel>
with this in the aspx.cs file:
protected void Page_Load(object sender, EventArgs e)
{
CollapsiblePanelExtender collapsiblePanelExtender = new
CollapsiblePanelExtender();
collapsiblePanelExtender.TargetControlID = this.ContentPanel.ID;
collapsiblePanelExtender.ExpandControlID = this.Panel.ID;
collapsiblePanelExtender.CollapseControlID = this.Panel.ID;
collapsiblePanelExtender.ScrollContents = false;
collapsiblePanelExtender.Collapsed = false;
collapsiblePanelExtender.ExpandDirection =
CollapsiblePanelExpandDirection.Vertical;
collapsiblePanelExtender.SuppressPostBack = true;
collapsiblePanelExtender.TextLabelID = this.TextLabel.ID;
collapsiblePanelExtender.CollapsedText = "Collapsed";
collapsiblePanelExtender.ExpandedText = "Opended";
this.panelExtenderContainer.Controls.Add(collapsiblePanelExtender);
}
HTH
Jonathan.