//submit login form
  function doChallengeResponse() {
    str = document.login.username.value + ":" +
          MD5(document.login.password.value) + ":" +
          document.login.challenge.value;

    document.login.response.value = MD5(str);
    document.login.password.value = "";
    document.login.submit();
  }

  // Activate the appropriate input form field.
  function ActivateLoginBox() {
    if (document.login.username.value == '') {
      document.login.username.focus();
    } else {
      document.login.password.focus();
    }
  }