Can you teach an old dog new tricks?

Simon - 06/01/93- 08/28/09

Easy does it!
Barked: Fri Jun 26, '09 11:00am PST 
Hi, there, we are new to this site. I've posted already in the forum section, but I thought it wouldn't hurt to post here too.

Simon has hip dysplasia which we are treating right now with adequon shots. (4 more weeks to go). He can't go down the stairs anymore. He seems to be able to get around on flat surfaces. I am trying to re-route his routine and take the elevator to get outside, but he pees on the way about half the time. I have bought doggie diapers so there are no accidents in the hallway. I've tried luring him with a treat to distract him. Despite his age, he gets around pretty well otherwise.
Does anyone have any other kind of advice for us?