How to reject some NotificationMessage to the ChatRoom

Hi!

We are making some plugins to the Spark/Wildfire to meet some requirements from our users. One of the req. is to remove the notification about:

Entering a ChatRoom

Leaving a ChatRoom

(these are simple green messages in the TranscriptWindow, and you can make some yourself by TranscriptWindow.insertNotificationMessage("…"). I want to trap this, and reject those messages shown above.

The message Filter seems not help me doing this.

Is there any out there who knows how to do this, I would be very happy

Regards

Per Kare Foss