Yes at the bottom of the edge of the door there should be a small hole. If you insert a screwdriver you can adjust the height the door travels above the door frame (normally turning clockwise raises the door). Note that there is a wheel at the front and the back edge and both probably need to be adjusted. The adjusting screw may have seized so spraying it with anti-seizing fluid such as WD40 or light oil should help.
G
January 2008