Web developer can use the ScriptManager class method RegisterDataItem to add custom information. This method accepts a Control instance and the value associated with it. The value can even be a class. The value will be serialized on the client in JSON format.
In C#: sm.RegisterDataItem(this, “true”);
In VB.NET: sm.RegisterDataItem(Me, “true”)When data returns on the client, the application intercepts the moment the PostBack result is processed and inject the code. When the page is initially loaded, the application retrieves the PageRequestManager object through its static getInstance method, which is the component that intercepts the page PostBack and transforms them into Ajax calls. Then the application uses the add_endRequest method to pass a method that’s invoked when the client has finished processing the server data:
If you want to host ASP.NET AJAX application then you will need ASP.NET AJAX hosting provider which supports AJAX Framework.