package{
import flash.display.Sprite;
import flash.system.Capabilities;
public class Main extends Sprite{
public function Main(){
var os:String = flash.system.Capabilities.os.substr(0, 3);
if (os == "Win") {
trace("Windows-specific code goes here");
} else if (os == "Mac") {
trace("Mac-specific code goes here");
} else {
trace("Must be Unix or Linux");
}
}
}
}