Thanks for the Tkinter chapter, Mike!
diff --git a/Doc/ACKS b/Doc/ACKS
index 385b5f1..a3555d2 100644
--- a/Doc/ACKS
+++ b/Doc/ACKS
@@ -37,6 +37,7 @@
 Lorenzo M. Catucci
 Mauro Cicognini
 Gilles Civario
+Mike Clarkson
 Steve Clift
 Matthew Cowles
 Jeremy Craven