    <li><a href="#run2">Re-run the Encryption Checker &mdash; 1 error</a></li>

        <li><a href="#error2">Correct the second error</a></li>

        <li><a href="#run3">Re-run the Encryption Checker &mdash; no errors</a></li>

        <li><a href="#learnmore">Learn more about writing your own checker</a></li>

      </ol>
    </div>
  </div>

  <div id="setup">
    <h4>1. An Encryption Checker</h4>

    <p>As an example, suppose that you wish to only allow encrypted
    information to be sent over the i