HELP I dropped the latch down inside the sliding glass door frame.

Hi. I have an american standard sliding glass door. I recently purchased the kit to add a key lock to the outside. Well I unscrewed the screws holding the latch on the inside of the door and it dropped down into the door frame. I have tried magnets to pull it up, which didn't work. Now I just have a door with four empty holes. What part do I buy to replace the latch mechanism. I have the handles.

I have found a solution to this. It actually worked for me. If you turn the 2 roller adjuster screws on each side of the bottom of the sliding door counter clockwise as far as you can,you can then lift the door up and out. Then carefully, slowly turn it upside down & the lock will slide down to where you can fish it out. If you have a slider with blinds inside & they move when you turn it upside down, not to worry, when you flip the door back the right way, they will fall back into place. ?