Air conditioning problems on 2001 Chevrolet Cavalier

My air conditioning suddenly stopped working. I checked all my fuses and they were fine. I then bought a can of freon and a pressure gauge and it shows my A/C pressure to be fine (24 psi). What next?

there are four key parts to an air conditioner sys: the air conditonier, an evaporator condenser, compressor and of course the belt that drives it. I would check the belt first and than the compressor, if they are fine than look at the condensor.....