Where is stack?

[Bill Vlahos]

I want to be able to have the user easily make a copy of the stack they 
are working on as a way to backup the stack. This would be something 
like "Save a Copy".

However, I don't want to change the active path of the stack. I still 
want the stack they are working on to stay put and be the working 
stack.

The following button script doesn't work and gives this error
	Chunk: source is not a container

on mouseUp
   answer folder "Select destination folder for backup: "
   if it is not "Cancel" then
     revCopyFile this stack, it
   end if
end mouseUp

How can I make this work?

Bill Vlahos