Convert AS 3.0 to AS 2.0

1

I want convert the below code to AS 2.0 which is in AS 3.0

code is

this.fullscreen_btn.addEventListener(MouseEvent.MOUSE_UP, toggleFullscreen);
stage.scaleMode = “exactFit”;
function toggleFullscreen(event:MouseEvent) {
if (stage.displayState == “fullScreen”) {
stage.displayState = “normal”;
} else {
stage.displayState = “fullScreen”;
}
}