title: Two login forms result in anti-forgery token exception
body: <p>In my application sometimes i get the exception when I try to log in:</p>
  
  <blockquote>
    <p>A required anti-forgery token was not supplied or was invalid.</p>
  </blockquote>
  
  <p>I can't reproduce it in 100%, but it happens frequently.</p>
  
  <p>My <strong>guess</strong> is that is has something to do with multiple login forms on the same page.</p>
  
  <p>More precisely:</p>
  
  <ul>
  <li><p>On top of my page there is a small log in/out panel always visible.</p></li>
  <li><p>If the unauthorized user tries an action he's not supposed to, he gets redirected to a dedicated log in page.</p></li>
  <li>Than there are 2 different forms pointing to the same action.</li>
  <li><p>Both forms have:</p>
  
  <p>@Html.AntiForgeryToken()</p></li>
  <li><p>The log in action is decorated with:</p>
  
  <p>[ValidateAntiForgeryToken]</p></li>
  </ul>
  
  <p>My questions:</p>
  
  <ol>
  <li>Can this be the problem?</li>
  <li>If not, than what can it be?</li>
  <li>And of course how to fix it? </li>
  </ol>
  
  <p>Please note that:</p>
  
  <ul>
  <li>This top log in/out panel is in a partial, which is in a partial ... which is in the _Layout.cshtml</li>
  <li>The dedicated log in page is rendered as a body.</li>
  </ul>