Gridview nested in another grideview using CollapsiblePanelExtender

Hi guys,

Hope someone can help me.

I've got a gridview nested in another gridview. It is headers and lines. I'm using the AJAX control CollapsiblePanelExtender to expand/collapse the lines.

I bind the lines in the header_RowDataBound which means it binds all the lines of all the headers when the page loads.

It is taking a long time and i'd like to know if it possible to bind the lines when I click on a header to see the lines?

I can't really see any event that fires when I click on a header.

Any ideas?

Cheers