fix a lot of Tkinter imports
diff --git a/Demo/tkinter/matt/00-HELLO-WORLD.py b/Demo/tkinter/matt/00-HELLO-WORLD.py
index 20a2050..3b4092a 100644
--- a/Demo/tkinter/matt/00-HELLO-WORLD.py
+++ b/Demo/tkinter/matt/00-HELLO-WORLD.py
@@ -1,4 +1,4 @@
-from Tkinter import *
+from tkinter import *
 
 # note that there is no explicit call to start Tk.
 # Tkinter is smart enough to start the system if it's not already going.