I had to do the same with the Tutorial , I Just tried to do it again and I'm still getting the image opening in a new window. Not sure what I'm missing

Think I'm going to try this on my computer at home to see if its a configuration issue. Thanks for the help.

To follow up on this I finally figured out what was wrong. The tutorial I followed is completely wrong is say to add script/link tags to

<link href="@Href("~/Styles/lightbox.css")" rel="stylesheet" />
          <script src="@Href("~/JS/lightbox.js")" type="text/javascript"></script

When you need tags for 

         <link rel="stylesheet" href="Styles/lightbox.css" type="text/css" media="screen" />
        <script type="text/javascript" src="js/prototype.js"></script>
        <script type="text/javascript" src="js/scriptaculous.js?load=effects,builder"></script>
        <script type="text/javascript" src="js/lightbox.js"></script>