Air Condition is not blowing cold air? on 2000 BMW 323Ci

Hi all, there is no difference in air tempeture when i switch on the air conditioning i have take out the pollen filter and it didnt seem to be that dirty....anybody have any ideas what might be the problem here? thanks

1 answer
Make sure the compressor is running
Check for fan operation
Check the refrigerant and see if the system needs to be re-charged