i don't get scalable objects

Newbie & Debugging Questions
#1

I’m using class ScalableGame class, to get scalable objects with screen size, but nothing changes… So, what I’m doing wrong?

        
appGameContainer = new AppGameContainer(
     new ScalableGame(new AppStateController(), Settings.video.getWidth(), Settings.video.getHeight(), true)
);
appGameContainer.setDisplayMode(Settings.video.getWidth(), Settings.video.getHeight(), Settings.video.isFullScreen());
appGameContainer.start();