lineNumber += 1;
    System.out.println("i pressed it");
    this.repaint();
   }
  } else if (getGameAction(keyCode) == Canvas.UP) {
   if (lineNumber > 0) {
    lineNumber -= 1;
    System.out.println("i pressed it");
    this.repaint();
   }
  }
 }
}
 

package ui;  
import javax.microedition.lcdui.Canvas;  
import javax.microedition.lcdui.Display;  
import javax.microedition.midlet.MIDlet;  
import javax.microedition.midlet.MIDletStateChangeException;  
public class Screen extends MIDlet {  
    private Display display;  
    private Canvas canvas;  
      
    public Screen() {  
        display = Display.getDisplay(this);  
        canvas = new MenuCanvas();  
    }  
      
    protected void destroyApp(boolean arg0) throws MIDletStateChangeException {  
    }  
    protected void pauseApp() {  
    }  
    protected void startApp() throws MIDletStateChangeException {  
        display.setCurrent(canvas);  
    }  
}