Action Listener in main class
play.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
    Game g= new Game();
        add(g);
    }
});
Constructor of Game class
Game(){
    Container c=this.getContentPane();
    c.setVisible(true);
    this.setVisible(true);
    add(new g());
    addMouseListener(new ml());
        this.setBounds(100,100,200,300);
    this.setTitle("LEVEL 1:");
    for(int loop=0;loop<=10;loop++){
        ballfall();
}
ScoreScreen sc= new ScoreScreen();
sc.setmethod(String.valueOf(sum));
}
I am making a game in which the there is homescreen where user clicks playbutton and another screen appears where the main game is.The problem is when I click play button a blank black screen appears and nothing happens. But when I create Game oibject in main method , it works fine but it doesn't work when its object is created in Action Listener. I've even added the object g in add().
 
    