A recharge won't help if it has a bad leak. There are way to many possibilities as to what can be wrong with the A/C system. It could be full, and not blow cold, if the clutch on the compressor doesn't work, or the high pressure switch has failed. Take your car to a local mech. and get an estimate as to what's wrong, then post back with what they tell you.
Use the search feature here. There was a pretty good thread a while back on A/C systems.