Grab yourself a phillps screw driver and locate the part on the door frame where the locking latch(pushes in and out)not the locking tooth that secures the door when you go to lock it with a key.
Using the screw driver,there are to screws,loosen them both and then slide the mechnism towards you as you are facing the inside of the door,tighten them both up.
If that doesnt help,grab youself an allen key,there is a screw on the the locking latch on the door that you must loosen,turn it to loosen anti clock wise for about a half a turn,the latch should move forward towards you(dont take the screw out mind)
Mike
May 2006