Staying dry at night has NOTHING to do with potty training. If he uses the bathroom in the day then he is potty trained. Night time dryness will come when his body is ready. This is VERY, VERY common, especially with boys. Most kids are dry at night by age 6. Until then, put a mattress protector on his bed and/or let him wear Good Nights or Pull ups to bed. But remember that most kids who wet the bed sleep right through it. Their brains do not listen to the signals from their bladder and do not wake up to go. Again, time and more brain development take care of that. Also physical growth leads to a bigger bladder that can last all night.
Other things to try:
You can also try putting a little potty in his room for the night so he doesn't have to walk down the long, dark hall alone at 2am IF he wakes up and has to go.
Wake him for a potty run before you go to bed but hours after he went to sleep.
But do NOT limit fluids.
at 12:10 PM on May. 29, 2009