BSP handler close button (X) in window

Hi gurus,

Does anybody knows if is there a way to handler or execute a code when I press the close button (X) in a popup BSP window.

I have a popup which is created in a BSP extension.

My popup is created

The thing is I put a external break in the event EH_ONPOPUP , but is not been raised.

Any help is useful.

Thanks in advance.

Regards