I have the Problem when user press the Notification activity is open but notification can not be close help me

my code is

NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

    int icon = R.drawable.ic_launcher;
    CharSequence tickerText = "Good Morning";
    long time = System.currentTimeMillis();

    Notification notification = new Notification(icon, tickerText, time);

    Context context = getApplicationContext();
    CharSequence contentTitle = "Title";
    CharSequence contentText = "Text";
    Intent notificationIntent = new Intent(this, NotificationManagerDemoActivity.class);
    PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent,0);
    notification.flags = Notification.FLAG_AUTO_CANCEL;
    notification.setLatestEventInfo(context, contentTitle, contentText, contentIntent);
    mNotificationManager.notify(1,notification);