Let me explain why I can't answer your question.

Normally I love a good Tk problem.  Tk is fun to work with, and can almost always be made to do exactly what you want, even though it sometimes challenges you.

So when I saw your question, I immediately cut and pasted the text into a new program to try it.  Of course, I didn't get anywhere because it's far from complete.

Now think about it.  When you ask a question here, you're asking for help.  That means you have to meet us halfway.  Why should we have to guess what the beginning of your program looks like?!  That's extra work; likely to be useless, since we're not guaranteed to get the same error as you get.  All at once your question goes from a potentially interesting one to one I have no interest in solving.

Now I see you've asked a similar question before, so I went and looked at that one too.  Well, guess what?  You're expecting us to do your work for you there, too!  You're not going to get much help if you can't be bothered to show more of your problem.  Only you know what the rest of the program is; why should we waste our time trying to guess at it?