Maher K. Al-Jendasi aka ArcadianPassion

When you upgrade your site to use the ASP.NET AJAX Beta 2, you must add a new HttpHandler in the web.config file. Under the <httpHandler> element in the web.config, add the following handler:

<add verb="GET" 
  path="ScriptResource.axd" 
  type="Microsoft.Web.Handlers.ScriptResourceHandler" 
  validate="false"/>

Otherwise you may receive 'Sys' is undefined error message