fix a lot of Tkinter imports
diff --git a/Demo/tkinter/matt/two-radio-groups.py b/Demo/tkinter/matt/two-radio-groups.py
index 52513ba..38b61b1 100644
--- a/Demo/tkinter/matt/two-radio-groups.py
+++ b/Demo/tkinter/matt/two-radio-groups.py
@@ -1,4 +1,4 @@
-from Tkinter import *
+from tkinter import *
 
 #       The way to think about this is that each radio button menu
 #       controls a different variable -- clicking on one of the