Okay, I'll show my utter ignorance of OO and ask if OO in Perl is anything more (in a general sense, of course) than modularized subroutines? Aside from the global variables, I've broken the script up into numerous subroutines all of which operate (as much as is possible) independent of each other.

Also, of the 4000 lines, only about 750 are actually in the main loop of the Tk interface, the rest are taken up by the subroutines (21 in total). It's for this reason that the global variables worry me, because after a while it does become difficult to know where they have been littered throughout the subroutines and ensure that I haven't accidentally put them in a position of being modified (but I'm checking my code with a fine-toothed comb now, as the saying goes).

I'm going to see if I can get my hands on a copy of the OO Perl book, and will see what I can do about putting the globals into a module. Thanks for the responses!

matt