The notification can't skip to another activity?

my code is

public class AlarmReceiver extends BroadcastReceiver {
public Notification mNotification = null;
public NotificationManager mNotificationManager = null;

@Override
public void onReceive(Context context, Intent intent) {
    Toast.makeText(context, "time up！", Toast.LENGTH_SHORT).show();
    mNotificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    mNotification = new Notification(R.drawable.icon, "tip！",
            System.currentTimeMillis());
    mNotification.contentView = new RemoteViews(context.getPackageName(),
            R.layout.notification);
    mNotification.contentView.setTextViewText(R.id.tv_tip, "click to see the description");
    Intent notificationIntent = new Intent(context,NotificationTip.class);
    notificationIntent.putExtra("description", intent.getStringExtra("description")) ;
    //notificationIntent.setFlags(Inte开发者_JS百科nt.FLAG_ACTIVITY_NEW_TASK);
    PendingIntent contentIntent = PendingIntent.getActivity(context, 0,
            notificationIntent, 0);
    mNotification.contentIntent = contentIntent;
    mNotificationManager.notify(0, mNotification);
}

}

While when I click the item in notification ,I can't get to NotificationTip activity,so what's wrong with this code?

following line

 Intent notificationIntent = new Intent(context,NotificationTip.class);

needs to be

Intent notificationIntent = new Intent("X");

Where X is the intent action name. this you have to add as intent filter in your android manifest file.