Display push notification in alert box when the app is running in the foreground

I am doing push notification in my android app that is triggered by GCM. I want to display the notification if the app is running in a alert box,if the app is not running means not in the foreground just display the status bar notification, How do you determine if the app is running and is in the foreground?is this is possible to show notification like this.now am using this code for show status bar push notification

  NotificationManager notificationManager = (NotificationManager)
                context.getSystemService(Context.NOTIFICATION_SERVICE);
        Notification notification = new Notification(icon, message, when);

        String title = context.getString(R.string.app_name);

         Intent notificationIntent = new Intent(context, BottomActivity.class);
        // set intent so it does not start a new activity
        notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
        PendingIntent intent = PendingIntent.getActivity(context, 0, notificationIntent, 0);
        notification.setLatestEventInfo(context, title, message, intent);
        notification.flags |= Notification.FLAG_AUTO_CANCEL;

        // Play default notification sound
        notification.defaults |= Notification.DEFAULT_SOUND;

        //notification.sound = Uri.parse("android.resource://" + context.getPackageName() + "your_sound_file_name.mp3");

        // Vibrate if vibrate is enabled
        notification.defaults |= Notification.DEFAULT_VIBRATE;
        notificationManager.notify(0, notification);