title: Intercept Tkinter "Exit" command?
body: <p>I'm writing a client-server program in Python with Tkinter.  I need the server to keep track of the connected clients.  For this, I would like to have the client send an automated message to the server after the exit button(the standard "X" in the corner) is clicked.  How can I know when the user is exiting the program?</p>