title: Static types cannot be used as parameters
body: <p>I'm following the MVC Music Store tutorial, but I've just gotten a bit stuck with the Html Helper in part 5: <a href="http://www.asp.net/mvc/tutorials/mvc-music-store-part-5" rel="noreferrer">Part 5</a>.</p>
  
  <p>I seem to have followed it correctly so far (please correct me if I'm wrong :) )...however I am getting the following error:</p>
  
  <blockquote>
    <p>'musicStoreMVC.Helpers.HtmlHelper':
    static types cannot be used as
    parameters</p>
  </blockquote>
  
  <p>Here is the code from my application:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Web;
  
  namespace musicStoreMVC.Helpers
  {
      public static class HtmlHelper
      {
          public static string Truncate(this HtmlHelper helper, string input, int length)
          {
              if (input.Length &lt;= length)
              {
                  return input;
              }
              else
              {
                  return input.Substring(0, length) + "...";
              }
          }
      }
  }
  </code></pre>
  
  <p>If anyone can see what I'm doing wrong, or if more info is needed, I'd be grateful for the pointers!! Thanks.</p>