@Override
    public void actionPerformed(ActionEvent arg0) {
	Button key = (Button) (arg0.getSource());
	if (key.getBackground() == Color.RED) {
	    key.setBackground(Color.GREEN);
	    key.setLabel(ButtonText[0]);
	} else {
	    key.setBackground(Color.RED);
	    key.setLabel(ButtonText[1]);
	}
    }