[Javascript] Grab close window call

[Terry Riegel]

> My Safari browser occasionally, for no apparent reason, reports back
> to me "Do you really want to quit" and I always think "Yes, dummy --
> that's why I selected quit!"

Safari does that when the user has multiple window or tabs that will  
be closed as a result of the exit. I know this because it wasn't  
always this way and I have inadvertently lost several things in the  
past when quoting the wrong program.