Doors and Windows - Broken Sliding Glass Door Lock

I just moved into a small home built in 1974. I have a single-pane aluminum sliding glass patio door that is in very bad shape. The most significant problem is the door locking mechanism. The lock is shaped like a "J" and lifts up by a lever on the door to hook into a slot on the frame. This lock only works part of the time and needs to be replaced. Is it possible to just replace the lock? It appears as if the door has taken a lot of abuse over the years as it bows inward in the middle of the door so much so that you can put a finger between the two panels. I suspect it has been broken into once or twice. I will probably be replacing the door in the next year but would like to make it as safe and weatherproof as possible until then.

Colet

I've had success at the big orange box store finding replacement locks and/or repair parts for sliding doors.... On the other hand, is it the lock/// or the door frame "catch" that the "J-shaped mechanism" hooks onto? I have not had much luck with that piece....

In the meantime... a broomhandle cut to length and laid down in the framework functions extremely well keeping out unwelcome visitors.

Thanks for the encouragement. It is definately the "j-shaped" lock that is malfunctioning. It retracts into the door when you unlock it but it is hit or miss as to whether it will pop back out when you try to lock the door again.