Hi,
I suggest you go back in the archives of Mama Source and check out other responses to the same topic. There are even more insights from Smart Mamas.
My two tips are that we have a two or three time pee rule before bedtime. Once before brushing and washing and pjs, once before our bedtime activity and once before kisses and prayers. The other tip is to check out Hylands Homeopathic Bedwetting tablets they do work if you work them. The desmopressin that someone suggested did work for my daughter but our pediatrician said he wouldn't give it to a child before they were 10 or 11 because it is a strong medicine that wouldn't really work well yet as their bodies and bladders are still developing.
Also remember, different overnight brands fit different bodies differently. We just bought a store brand that did not work, 4 loads of laundry later I returned those and went back to the brand I knew worked.
Please remember that this is a body issue not a choice and treat it like someone needing glasses, it's just where his body is at right now.
Good luck,
T.