<html>
<body>

  <table>
    <form action="bug448564-echo.sjs" method="GET">
      <tr><td><input name="a" value="aval"></td></tr>
      <input type="hidden" name="b" value="bval">
      <input name="c" value="cval">
      <tr><td><input name="d" value="dval" type="submit"></td></tr>
    </form>
  </table>

  <script src="bug448564-submit.js"></script>

</body>
</html>