timer1 = new Timer(100, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent ae) {
            if (panel3.getWidth() != 406) {
                panel3.setBounds(0, 406, 0, panel3.getWidth() + 5);
                if (panel3.getWidth() == 406) {
                    timer1.stop();
                    System.out.println("Hello");
                    panel3.repaint();
                }

            }

        }
    });