public void startTimer() {
        node.setK();
    	gameIsStarted= true;
        Thread t;
        t = new Thread(new Runnable() {

            @Override
            public void run() {
                int seconds = 0;
                for (seconds = 5; seconds >= 0; seconds--) {
                    timerlabel.setText(""+seconds);
                    if (seconds == 1) {
                        isChairAppear = true;
                        for (int i = 0; i < numOpponent+1; i++)
                            arenaGame.addChair(chairs.get(i));
                    }
                    try {
                        Thread.sleep(1000);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        },"timer"
        );
        t.start();
    }