title: how does using HtmlHelper.BeginForm() work?
body: <p>Ok so I want to know how </p>
  
  <pre><code>&lt;% using (Html.BeginForm()) { %&gt;
    &lt;input type="text" name="id"/&gt;
  &lt;% } %&gt;
  </code></pre>
  
  <p>produce</p>
  
  <pre><code>&lt;form&gt;
    &lt;input type="text" name="id"/&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>namely how does it add the <code>&lt;/form&gt;</code> at the end? I looked in codeplex and didn't find it in the htmlhelper. There is a EndForm method, but how does the above know to call it?</p>
  
  <p>The reason is I want to create an htmlhelper extension, but don't know how to close out on the end of a using.</p>
  
  <p>Any help would be appreciated :)</p>