A/C question on 2002 Honda Accord

turn the A/C on, blow air out but not cold, switch to heater is hot.
what cause the A/C not cold. please help me out this issued.
how much cost for repair.
Thank you.

Asked by for the 2002 Honda Accord
Several possibilities, the most common being that the system is low on refrigerant, but only an inspection by a trained mechanic will answer that question.