Beginning Tkinter problem

[John Purser]

When working in IDLE(2.2) on Win2000 and attempting some Hello world class
programs I get stuck after entering this code:
>>> from Tkinter import Label
>>> widget = Label(None, text='Hello GUI World!')
>>> widget.pack()
>>> widget.mainloop()

The little window pops up, I click on the x in the corner and the window
disappears.  But I never get my IDLE interactive prompt back.  Even going
into the task manager and killing it there takes a while.

So what am I doing wrong?

Thanks,

John Purser