Quitting on a Mac

[Thomas Speitel]

I have a shutdownrequest handler for a Mac System 10 application that  
gives the user opportunity to save a field's contents before  
quitting. I realized that the field disappears before it can be saved  
so I put the following script in the menubar to capture the contents  
into a variable that could be saved.

--menubar script
on mouseDown
   global datacontent
   get the htmltext of field "data" of cd 1
   put it into datacontent
end mouseDown

Everything works fine now if the user quits using a mouse and goes to  
the quit menu item. What I don't know is how to intercept a command- 
Q??? Any ideas?
Thanks
Tom