Ford Repair: air-conditioning, mid 1990s, stop leak

Question
My air conditioner in my 2001 Ford Escort has stopped working. It blows air, but the air is just bareley cool. Would refilling the "freon" myself solve the problem? If so, at what point did Ford switch from R-12 to R-134a? (my car is a 2001 model) Am I good to go to just use R-134a or do I need to go to a mechanic to have my system adapted to switch from R-12 to R-134a? Can I still get R-12 myself? Thank you for any advise you can provide.

Answer
You can buy R-134A for your Escort, but you might be better off having it checked out. If there is a leak you may lose your investment in R-134A. Do not mix R-12 with R-134A. R-134A came into use in the mid-1990s. And please don't use ANY kind of AC stop leak or such products, they will clog the system and make the system more expensive and troublesome to service in the future.