A/c

My 1997 lumina 3.1 A/C is working fine but when I step on the gas the air stops coming out. It sounds like it is going up into the dash but as soon as I let off the gas it is fine. Can someone please help. Thanks.

Sounds like the problem described and resolved here:
http://www.automotiveforums.com/vbulletin/showthread.php?t=420464

Let me know if that solves it; if not, it might be the vac-elec solenoids under the glovebox...