Teresa, my daughter wet the bed until she was 6. For her, her bladder just needed to grow (plus she was a deep sleeper). When she was younger she couldn't hold urine very long at all. If she told me that she had to use the bathroom while we were out I had minutes to find a bathroom. When she would urinate it would come out with all this force (you know what it sounds like when your bladder is full) but she wouldn't have that much urine. Eventually, her bladder grew. She can now hold urine much easier (she's 8) and there isn't this forceful sound anymore and she pees more at one time. Rewarding your son isn't going to help because he can't help it. Keep him in the pull up until he wakes up dry.