accordinepane1 onclick event

Hi The theard continues on from this

http://forums.asp.net/t/1934206.aspx?accordinepane1+onclick+event

After adding this,

<asp:AsyncPostBackTriggerControlID="Accordion1$AccordionPane1$LinkButton2"EventName="Click"/>

im getting this error

A control with ID 'Accordion1$AccordionPane1$LinkButton2' could not be found for the trigger in UpdatePanel 'UpdatePanel2'.

Description:An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: A control with ID 'Accordion1$AccordionPane1$LinkButton2' could not be found for the trigger in UpdatePanel 'UpdatePanel2'.