Modification to dating site php file

Ok, What I need done to the attached script is the 3 things listed below. 1. What I need done is a I need the member results that show up from the search to be in order from who joined last should show up first in the search. 2. Also I need it added to the script and a place added in the database so that when a intro letter from a lady is sent to a man it will mark this man in the database so this same lady cannot send a letter to him again. 3. I need it added so when a lady puts something like the code: <NAME> into the intro letter the system will automatcally get the mans name from the database field and insert this into the intro letter replacing the <NAME> code.