Need a correct lock for my sliding glass door

Hello,

We cant be sure of what you need without seeing the original mortise lock but the 82-218 would be a good place to start. This lock commonly falls into the channel of the door frame since there is no faceplate to hold it in place once the screws are removed. Review the specification below to see if it would fit your door. Thanks for posting! 

Profile view of 82-218

Opposite side view 82-218