public Board(int difficulty) 
    {
        mode = difficulty;
        this.addKeyListener(new TAdapter());
        setFocusable(true);
        setDoubleBuffered(true);
        ingame = true;
        level1 = true;
        level  = "1";
        level2 = false;
        level3 = false;
        level4 = false;
        won    = false;
        
        
        setSize(1000, 700);
        startTime = System.currentTimeMillis();
        craft     = new Craft(mode);
        
        initAliens(20);
        Sound.MAINMUSIC.loop();
        
        timer = new Timer(5, this);
        timer.start();
    }