DD started doing this as well so I did her up a stickers reward chart. She gets a sticker for every wee/poo she does on the potty and then after a few stickers (whatever number you want to use) she gets a reward. I like this way because it is positive reward for going to the potty. Now DD screams "wee/poo mummy get sticker" So cute and she loves to pick out the sticker to put on her chart and is so proud showing daddy how many stickers she has gotten during the day when he gets home from work. Well actually she shows anyone who walks in our door - including trying to show the postmas yesterday, LOL!