The ASP.NET AJAX UpdatePanel gets updated in one of 3 ways.

1.) An implicit control event triggers an update (that is a control inside the UpdatePanel is getting updated, etc.)

2.) The UpdatePanel has a <Triggers> Collection, and one of the defined triggers gets fired.

3.) The UpdatePanel’s Update metod is explicitly called in the course of some server side logic.

BUT…….  What if I want to explicity trigger an update to the UpdatePanel from my client side JavaScript code ???

Ceck out his link on CodeProject for a solution.