Reverse AJAX?

Has anyone tried doing anything RAJAX (asyncronously send from server to client) with .NET? If so, could you point me in the direction of a reference? I need to write a small script or app that waits for messages on the server and notifies a client that a message has been received. I can't find anything out there for Microsoft technologies in regard to this, or even a set of white papers fro RAJAX.

Tim

hello.

i think that this kinf of application is also known as comet. some links that might help you:

http://en.wikipedia.org/wiki/Comet_%28programming%29

http://dojotoolkit.com/

http://dojotoolkit.com/

http://www.ajaxian.com/archives/comet-a-new-approach-to-ajax-applications