After letting ASP.Net Web Administration configured my web.config. I received “sys is undefined” error on the page whenever there is AJAX control on the page. There is nothing wrong with the code. All you need to do is to ensure the following statements exist in web.config:

<location path=”ScriptResource.axd”>
<system.web>
<authorization>
<allow users=”*”/>
</authorization>
</system.web>
</location>

<add verb=”GET” path=”ScriptResource.axd” type=”Microsoft.Web.Handlers.ScriptResourceHandler” validate=”false”/#62

Here is the related link:

http://blogs.wdevs.com/sebastien.lachance/archive/2006/11/23/17758.aspx

Related posts:

1. Learning ASP.Net AJAX (1)