In this tutorial, you will extend the UpdateProgress control with client behavior by writing ECMAScript (JavaScript) code. Your code will use the PageRequestManager class, which is part of the Microsoft AJAX Library. In the UpdateProgress control, you will add a button that enables the user to cancel an asynchronous postback. As part of this task, you will use client script to display or hide progress messages.
This topic assumes that you understand the UpdateProgress control. If you don't know, see the topic UpdateProgress Control Introduction.
Prerequisite
To implement these procedures in your own development environment, you need to:
Microsoft Visual Studio 2005 or Visual Web Developer Express Edition.
An AJAX-enabled ASP.net web site.
To cancel an asynchronous postback in client script
Create a new ASP.net Web page and switch to Design view.
In the AJAX Extensions tab of the Toolbox, double-click the ScriptManager control, the UpdatePanel control, and the UpdateProgress control to add an instance of each control to the page.