fix a lot of Tkinter imports
diff --git a/Demo/tkinter/matt/canvas-mult-item-sel.py b/Demo/tkinter/matt/canvas-mult-item-sel.py
index a4f267c..4875b44 100644
--- a/Demo/tkinter/matt/canvas-mult-item-sel.py
+++ b/Demo/tkinter/matt/canvas-mult-item-sel.py
@@ -1,4 +1,4 @@
-from Tkinter import *
+from tkinter import *
 
 # allows moving dots with multiple selection.