Updating your web config to enable asp net ajax
It then checks to see whether an error was reported, and if so, processes the details of it, finally indicating to the runtime that the error was handled in custom script.
The Script Manager control provides extensive support for localization of script strings and user interface components; however, that topic is outside of the scope of this whitepaper.
Enabling partial rendering with this default page is as simple as revisiting Step 10 of this walkthrough and dropping controls onto the page.
When the postal code is entered by the user, the Update Panel detects the event (the corresponding Text Changed event in the back-end, either by specifying triggers or by using the Children As Triggers property set to true).Each Update Panel is isolated, so that each can work independently (you can have two Update Panels running at the same time, rendering different parts of the page, independent of the page's postback).The Update Panel control primarily deals with control triggers - by default, any control contained within an Update Panel's that creates a postback is registered as a trigger for the Update Panel.AJAX posts all of the fields within the Update Panel, as captured by Fire Bug (see the diagram on the right).As the screen capture indicates, values from every control within the Update Panel are delivered (in this case, they are all empty), as well as the View State field.