Dori-boy

I have a 99' IS200 that I have bought from my Brother. Im very happy with it apart from the fact I cant change what air vents the blowers blow air from. Its not to bad at the moment, but im sure a soon as the winscreen mists up im going to be stuffed as I cant get it to blow onto the screen. Ive had the heater control apart and it all seems ok and in tacked and everything else works fine. Any help with this guys would be great. Dave.