@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.bell_activity);
        bell_iv = (ImageView) findViewById(R.id.bell_iv);
        bell_iv.setColorFilter(Color.parseColor("#ff6f00"));
        unmutesounds();
        mp = MediaPlayer.create(this, R.raw.bell);
        mp.setLooping(true);
        mp.start();
        countdown = new CountDownTimer(60000, 60000) {
            @Override
            public void onTick(long arg0) {

                finish();
            }

            @Override
            public void onFinish() {

            }
        };
        countdown.start();
    }

    private void unmutesounds() {
        AudioManager amanager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
        amanager.setStreamMute(AudioManager.STREAM_NOTIFICATION, false);
        amanager.setStreamMute(AudioManager.STREAM_ALARM, false);
        amanager.setStreamMute(AudioManager.STREAM_MUSIC, false);
        amanager.setStreamMute(AudioManager.STREAM_RING, false);
        amanager.setStreamMute(AudioManager.STREAM_SYSTEM, false);

        int maxVolume = amanager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
        float percent = 0.9f;
        int seventyVolume = (int) (maxVolume * percent);

        while (amanager.getStreamVolume(AudioManager.STREAM_MUSIC) < seventyVolume) {
            amanager.adjustStreamVolume(AudioManager.STREAM_MUSIC,
                    AudioManager.ADJUST_RAISE, AudioManager.FLAG_SHOW_UI);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        if (countdown != null) {
            countdown.cancel();
        }
        if (mp != null) {
            mp.stop();
        }

    }