I have a a CollapsiblePanelExtender with the usual extend and collapse buttons....I would like to have a click event fire off when the extender is extended and a different click event fire off when the extender is collapsed. But the most important event is when it is extended. I could live without a click even on collapse.

Most of the examples I've found online searching using: CollapsiblePanelExtender click event is having the extender react based on a click even else where...

I want the extender to fire off a JS when clicked.

How should I go about accomplishing this?
Am I asking the wrong question/using the wrong search strings?

            CollapsiblePanelExtender extendatron = new CollapsiblePanelExtender();

            extendatron.ID = cpe + MenuId;

            extendatron.TargetControlID = pnlContent + strMenuId;

            extendatron.ExpandControlID = pnlMenu + strMenuId;

            extendatron.CollapseControlID = pnlMenu + strMenuId;

            extendatron.Collapsed = bCollapsed;

            extendatron.TextLabelID = strMenuName;

            extendatron.ExpandedText = m_strButtonLabelHide;

            extendatron.CollapsedText = m_strButtonLabelShow;

            extendatron.ImageControlID = imglnk + strMenuId;

            extendatron.CollapsedImage = ~/App_Themes/default/nbExpand.gif;

            extendatron.ExpandedImage = ~/App_Themes/default/nbCollapse.gif;

            extendatron.SuppressPostBack = true;

            extendatron.ScrollContents = false;



            var extender = $find('extendatron'); //this would be <%=myExtender.ClientID%>

            extender.add_collapsed( function() { alert('collapsed'); });

            extender.add_expanded( function() { alert('expanded'); });