Fscommand Prob

Hello, simple question, i already looked up in previous threads about this but im still having trouble, i have a 800 x 600 workspace, and 2 layers 1 has a picture as background and the other layer has 1 frame with this code:

fscommand("fullscreen", "true");

and i test my movie and nothing happens, it stays the same size… i don’t know why just does nothing… so is there another way to get fullscreen ? or am i doing something wrong?

the code is placed in an empty keyframe on the first frame of my movie… thanks