Trapping the Close Window Action

[Dave]

Hi,

Is there anyway to trap the Close Window action? e.g. when the user  
presses the red close window button on Mac or the X on Windows.

I know I can use closeStack but this gets called regardless of  
whether the window was closed due to the button being closed or if  
it's closed from the Script. In the former case I want to quit the  
application.

Thanks a lot
All the Best
Dave