fix a lot of Tkinter imports
diff --git a/Demo/tkinter/matt/canvas-with-scrollbars.py b/Demo/tkinter/matt/canvas-with-scrollbars.py
index b55215d..1c5681a 100644
--- a/Demo/tkinter/matt/canvas-with-scrollbars.py
+++ b/Demo/tkinter/matt/canvas-with-scrollbars.py
@@ -1,4 +1,4 @@
-from Tkinter import *
+from tkinter import *
 
 # This example program creates a scroling canvas, and demonstrates
 # how to tie scrollbars and canvses together. The mechanism