Sys is not defined Error and ajax update panel VS2010

i think my web.config has missing some entries. when i add line like in my aspx file

Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endRequestHandler);

function endRequestHandler(sender, args) {
    alert('Update Panel work is done');
}

from that time i am getting error like Sys is not defined. i am developing site in VS2010 ASP.Net & C#.

here i am giving my web.configs entries.

please some one rectify my web.config or tell what i need to add in my web.config under which tag in detail.

here is my web.config detail

<?xml version="1.0"?>

开发者_StackOverflow中文版

You will have to compare your web.config to the standard web.config tags..

try http://www.technade.com/2008/09/required-entries-in-webconfig-file-for.html

or http://littletalk.wordpress.com/2008/12/07/webconfig-for-using-ajax-tool-kit

.net 3.5 https://web.archive.org/web/20211020153237/https://www.4guysfromrolla.com/articles/121207-1.aspx