@Override
        public void stateChanged(ChangeEvent e) {
            switch(((JTabbedPane)e.getSource()).getSelectedIndex()){
                case MY_HISTORY:
                    if(!changed[MY_HISTORY]){
                        changed[MY_HISTORY] = true;
                    }
                    break;
                case MY_STEPS:
                	if(!changed[MY_STEPS]){
                		changed[MY_STEPS] = true;
                		steps.renewChart();
                	}
                    break;
                case MY_ACHIEVEMENT:
                    if(!changed[MY_ACHIEVEMENT]){
                        changed[MY_ACHIEVEMENT] = true;
                        achievement.update();
                    }
                    break;
                case OUR_DIFFERENCE:
                    if(difference.getOppID() == null)
                        difference.askForUserID();
                    break;
                case SUBONLINE:
                        submit.askForProID();
                    break;    
                default:
                    break;
            }
        }