Unfortunately, trying to put it up/down has probably made the problem worse. The window regulator, which moves the glass, is a cable system. More than likely the cable is jammed inside the pulley and there's nothing you can do but fix/replace the regulator.
I replaced mine myself. It's a pretty easy job. Adjusting the glass is the most difficult part. Here's the DIY:
http://www.1addicts.com/forums/showthread.php?t=880902