HAHAAA Yeah I wont buy it at work I go to wally mart. I do have a leak but putting a condensor in mine is a real bisatch so I bought some stuff to try so far so good.How long has the A/C been blowing warm? If its been awhile, you will need to find the leak (dye charge and leak detector equipment) and fix it. Also if the system is opened, the reciever/dryer MUST be changed or the system will fail again. I see it all the time.
My truck had the evaporator replaced 2 years ago. This year the compressor would cycle frequently (low charge). I took a gamble and charged the system with 4 cans of Interdynamics high mileage leak sealer freon (bought at WalMart). Pretty pricy at $10/can (1 lb), however, system is holding charge and blowing 40 deg air.
It must be pretty good stuff because all the Wal Marts near me were out of stock for the month of July. They had plenty of regular R134A, but none of the High mileage.