Force an UpdatePanel Update from JavaScript
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.
https://www.codeproject.com/useritems/UpdatePanelScriptExtender.asp