AJAX :: Implement Slideshow Extender With A Code Behind File?

I have found all kinds of tutorials on the web showing how to implement the AJAX slideshow extender, but can't get them to work. All I want to do is put a simple slideshow on a master page. I want to use a code behind file for the c# (do not want the script on the page itself.

I ran into a couple of problems with the samples on the web. Specifically when I try to add System.Web.Services.WebMethod and System.Web.Script.Services.ScriptMethod - VS 2010 doesn't know what the "WebMethod" or the "ScriptMethod" are. Further, VS2010 express keeps telling me "{" expected - on the line AjaxControlToolkit.Slide[] slides = new AjaxControlToolkit.Slide[5];

Every tutorial on the web seems to be for ASP.net 2.0 - and is at least 2 years old. Is there an easier way in ASP.Net 4 to implement the slideshow control? I am new to c# in general, so if someone could provide a simple cs codebehind file - and the code on the aspx page, that would be great. I understand more than I can write.