T.R.
When I potty trained my boys, I used a "potty chart". Everytime he used the potty, he put a star sticker on the chart. When he had an accident, he put a sad face on his chart. At the end of the week, if he only had a few sad faces (or none later on) we would let him pick out a small toy at the store. My boys responded well to seeing all the stars on their charts (and had fun with the stickers).