Potty training

I'm potty training my 2 1/2yr old and he does it fine when we are at home with just the family but at night when hes asleep or when we go out he completely forgets to tell me to take him to the bathroom? what should I do?

Get in the habit of asking him at times where he might need to go. The fact that he is potty trained during the day alone is commendable but it could just be the issue of remembering when he's not at home or during the night. He is just 2 1/2 and they forget things like using the bathroom, cleaning their hands, sometimes even eating. If you continue to ask him consistently after a meal or every couple of hours when you are out, then he will begin to realize that he needs to check with himself every now and again to see if he has to go. When he does go in public congradulate him greatly and speak highly of his achievement. Don't be too worried about his situation just give him some time, he'll get the hang of it.