need help in installing ASP.NET ajax tool kit in 4.5 VS 2012 website project

I am trying to install  ASP.NET ajax tool kit in 4.5 VS 2012 website project.
I came across this tutorial: http://ajaxcontroltoolkit.codeplex.com/
Even tho the tutorial is for 4.0 framework, I installed AJAX Tool KIT via NetGu.
Now I am getting this error, why ?
Server Error in '/' Application. -------------------------------------------------------------------------------- The assembly 'AjaxControlToolkit, Version=4.5.7.1002, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e' does not contain a Web resource that has the name 'MsAjaxBundle'. Make sure that the resource name is spelled correctly. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Excepti ...