Terry,
I'm glad your having good luck with this approach! I'm keeping my fingers crossed that it continues to help with your difficult child's behavior.
It's similar to what I do in my house. My kids get reward time for good behavior and loss of reward time for bad behavior. Whenever possible, I like to use natural consequences. Natural consequences seem to sink in better... Although sometimes it's hard to tell if anything sinks in at all!!! :grrr: