Brakes Locked?

We have a 2000 Sephia; my son drives it and he pulled into a QuickTrip, when trying to leave it would not move foward or backwards, I went to see what the problem was and it seems that the brakes have locked up I tried rocking it back and forth in Drive, Reverse and Netural and it would not budge, it acts like when giving it gas that the E-Brake is on, but the E-Brakes has not worked on this car for a long time he told me, he said you can set the E-Brake but it had no effect.
He has never had this problem before and the car was acting fine when he parked it.
Anyone ever had this problem?
We have had heavy rain for two days I wonder if the moisture has anything to do with this, driving through large puddles etc.
I left it there for the night and will check it out in the morning, first thing I will do is jack up each wheel and see if any of them are locked up and go from there.
If anyone has any ideas I would greatley appericate hearing from you.
Thanks
Steve