split screen script help

I need help with a split screen script that i found… i did what it told me to do(renaming the cameras, ect.) but i just cant get the second camera to work! plz help me!

here is the script:

# need to get game window size so...
import Rasterizer
# get  list of objects in scene
objList = GameLogic.getCurrentScene().getObjectList()
# get player 1 camera named "Cam1"
viewCam = objList["OBCam1"]
# get player 2 camera named "Cam2"
viewCam2 = objList["OBCam2"]
# set player 1 cam bottom half of screen
viewCam.setViewport( 0,
                    Rasterizer.getWindowHeight()/2 )

# set player 2 cam top half of screen
                    Rasterizer.getWindowHeight() )
# use split screen

what i did is put in that code into blender, renamed my two cameras Cam1 and Cam2, added some logic bricks (2 always sensors for the cameras and a python controller), connected them, and all that will come out is the screen will split, top and bottom, and on the top will be what the first camera sees and on the bottom there wont be anything!
plz tell me what im doing wrong!