fix a lot of Tkinter imports
diff --git a/Demo/tkinter/guido/optionmenu.py b/Demo/tkinter/guido/optionmenu.py
index 7365fa6..1e72aa5 100644
--- a/Demo/tkinter/guido/optionmenu.py
+++ b/Demo/tkinter/guido/optionmenu.py
@@ -1,6 +1,6 @@
 # option menu sample (Fredrik Lundh, September 1997)
 
-from Tkinter import *
+from tkinter import *
 
 root = Tk()