sensing window destruction

[Michal Porzuczek <mporzuczek gmail com>]

Hi,

I was wondering how it is possible to sense when a widget is closed by
the user and send change a specific variable as a result.

Furthermore, is there a way other then gtk_widget_destroy to
destroy/close widget windows because this causes seg faults for me in
some occasions and in others dosen't actually close windows.

Thanks,

Michal