title: How can I use IHTMLDocument6 or other IE 8 interfaces from C#?
body: <p>I'm trying to access the <code>IHTMLDocument6.documentMode</code> property from my IE BHO, but that interface is not defined in any of the mshtml assemblies I can find on my machine.</p>
  
  <p>I've tried hacking together an interface definition for the interface:</p>
  
  <pre><code>[Guid("30510417-98b5-11cf-bb82-00aa00bdce0b")]
  [TypeLibType(4160)]
  public interface IHTMLDocument6
  {
      [DispId(1104)]
      float documentMode { get; }
  }
  </code></pre>
  
  <p>I can successfully cast the document object to this interface, but I do not get a value that makes sense for the <code>documentMode</code> property.</p>
  
  <p>Where can I find the version of mshtml that includes the <code>IHTMLDocument6</code> interface, or a correct version of the interface definition to use? Or is there some other way I should be doing this?</p>
  
  <p>Thanks.</p>