private TicketJPanel getRightPanel() {
   if (rightPanel == null) {
     rightPanel = new TicketJPanel();
     rightPanel.setBackground(Color.RED);
   }
   return rightPanel;
 }
 private TicketJPanel getLeftPanel() {
   if (leftPanel == null) {
     leftPanel = new TicketJPanel();
     leftPanel.setBackground(Color.BLUE);
   }
   return leftPanel;
 }