title: window external null?
body: <p>When i want to use window.external on internet explorer 9, it's always null.
  I want to use pinned methods but it cannot find the methods because of window external is null. 
  if wonder that what is "pinned" you can check this link.
  <a href="http://msdn.microsoft.com/en-us/library/gg131029(v=vs.85).aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/gg131029(v=vs.85).aspx</a>
  Can any body help me for this ? </p>