fix a lot of Tkinter imports
diff --git a/Demo/tkinter/guido/mbox.py b/Demo/tkinter/guido/mbox.py
index 88b0b89..45c384e 100755
--- a/Demo/tkinter/guido/mbox.py
+++ b/Demo/tkinter/guido/mbox.py
@@ -9,7 +9,7 @@
 import string
 import mhlib
 
-from Tkinter import *
+from tkinter import *
 
 from dialog import dialog