Potty Training...HOORAY!

So we are deep in the throes of potty training right now. We have had Jordan in underwear for 3 days and he has gone in the potty a few times, but mostly it has been LOTS of accidents. We are trying to stay positive and supportive and take him as often as possible. He is very good about telling us as he's going or immediately after, so he is aware. It's just very frustrating. I hope we can get through this very soon. He's such a smart boy, we just need to find the key to the potty thing that will flip the switch in his brain. Any and all suggestions would be greatly appreciated.