event / callback options in ASP.Net Ajax from server to client?

Question

Hi everyone,

I'm new to ASP.Net Ajax and wondered if the following was possible.

I'm thinking of putting in an updatepanel in a page with an update progress bar in it.

The idea is for a post from a button in the updatepanel to trigger a method call in the codebehind that calls a server component. I would, ideally, like for the server component to raise events periodically and bubble those back to the progress bar for display.

I can certainly put some events in the server component and fire them whenever I need to. The question I have is how to connect those event handlers in the code behind (not impossible I assume), then propagate them to the updatepanel?