You don't mention the car make or model...
On my Golf this has happened to both front windows - to get access to the glass I take off the inside grab handle and remove three screws really low low down on the inner trim panel which then lifts off vertically.
The window mechanism is all hidden inside the door cavity and carried on a metal plate. Rubber access disks can be removed to undo the window clamping screws and the window lifted up and taped to stop it falling down.
The carrier plate can be unscrewed and removed - the motor drives cables running over pulley wheels and carrying the lifting brackets - the cables often break and a new mechanism without the motor costs about £50. The original window motors are still working fine.
Your car may be different but you still have to remove the inner trim panel to see what's happened.
Sadly the window plate on my Golf also carries the door speaker and the pop rivets have to be drilled out to swap the speaker over to the new window mechanism.
Good luck...
Peccavi
March 2009