How-to question using Tk

[Mark Halley]

I've created a message box using TK that displays a simple message to the user while my script runs.  Everything works, but I've been unable to figure out how to center the message box in the user's monitor and how to make it 'stay on top'.  If a lot of windows are opened, the message box sometimes appear behind other windows unknow to the user.   Is this possible?   Thanks! Mark