Heating and Cooling problem

I have a 2004 Chevy Monte Carlo. The drivers side only gives off cold air even when it is on heat. The passenger side has no problems. Any ideas on what it could be or how to fix it?  

guessing it has dual climate control. if the battery has been replaced or disconnected it could cause problems. if so try disconnecting it again with the hvac system off reconnect it. start the car, let it run for a couple minutes without touching the controls. the car will go through a relearn process. if that doesn't work you probably need a new drivers side temp actuator.  

All that crap for dual climate control. Sometimes I question all these modern conveniences.  

overdesigned! how much of these modern creature comforts are really worth the hassel?  
luck is when skill and opportunity meet

The only modern comforts I use are cruise control, power locks & windows and the radio. Other items are just luxury.