Newbie: How to touch "global" variables

[Jeff Layton]

Hello,

   I've got a defeinite newbie question (I searched some,
but to be honest I don't know what keywords to search
on - which has brought me here :).
   I want a module to be able to "touch" a variable defined
globally (from the main script). I don't necessarily want
to change the value ofthe variable, but to query it. For
example, get the length. How do I do this?

Thanks!

Jeff

P.S. If someone needs some sample code I can cook
something up.