Chevrolet G20 van 1988 How do you put the rear bench seat back up?

Chevrolet G20 van 1988 Just bought it. Rear bench seat lays down to make a bed. how do you put it back up? I tried pulling it back up but it doesn't move. I don't see any latches or levers anywhere!|||some have a electric switch, look for it on the side pillars. call whomever you bought from. if not, look in the front behind the knee area or just under that area.