Potty Training - the next stage

Potty training has been going good.  One day my husband Anton and I just decided to let the boys know that they had to wear underwear during the day and diapers when they were sleeping.  No ifs ands or buts.  In the beginning there were some accidents, but since then they have been telling us that they need to use the potty.  I also gave them stickers when they successfully peed or pooped on the potty.  When they reached certain milestones they then got a chocolate bar.  I also found that they were more willing to use the potty when I did not make them use the baby potty seat on the regular seat.  I guess they wanted to feel like a big kid.