driver side window

sounds like the guide clip is broken or missing. Be sure the window is still in the track that it follows when going up and down. Next check to see if the guide clip is attached to the back side of the window. It is a plastic clip that attaches to the window closest to the outside door handle. It rides up and down the rear track keeping the window from tipping forward. If all that checks out ok then you may have a broken window regulator. The replacement clip or regulator are available at your local auto parts stores.