Joe is right.
Suzuki, in their infinite wisdom, decided that the dash panel vents would only blow cool air (air conditioned or not) and hot air would only get routed to the lower vents (legs) or the defroster. The defroster vents also include the side vents on the ends of the dash that point directly at the side windows.
If the slide bar on the dash control doesn't shift the setting very well (from defrost to legs) then the control bar on the passenger side of the unit may be bent. Look under the dash next to the passengers left knee and you will see the bar that comes down to control the flap.
Hope this helped a little. And Welcome!