3 year old son

My son is 2 months away from 3 yrs old, and we are working on potty training right now. I tried for a few months to get him to use the potty while he was still wearing diapers, and no luck. A couple days ago, we went to the store, let him pick out special underwear that he liked (Cars), and told him that he would not be allowed to wear diapers anymore. If he made a mess in his underwear that he would be in BIG TROUBLE! He has only had one accident so far and this is day 4. The first day he peed himself, he told me and without actually meaning to, I made him feel really bad about it. I told him that it was nasty, he made a big mess and he peed on Lightning McQueen. I made him wear the messy underwear for about 10 minutes in time out. I did not yell or get really upset, but he knew that he was in trouble. Since then, he tells me everytime he needs to go and let me know after his timeout that he would not pee on McQueen anymore. I think the most important thing to do is follow through. If you tell your son you are going to do something, then do it. Ask him frequently if he needs to use the potty and keep reminding him that he better not make a mess in his underwear or he will be in trouble. This is what worked for us, and I hope my experience helps a little. Good Luck!