        <ul id="menu">
          <!-- put class="selected" in the li tag for the selected page - to highlight which page you're on -->
          <li id="menu_index"><a href="index.php">Home</a></li>
          <li id="menu_scalemodels"><a href="scalemodels.php">Scale Model Building</a></li>
          <li id="menu_movies"><a href="movies.php">Movies</a></li>
          <li id="menu_observations"><a href="observations.php">Observations</a></li>
          <?php
          if ( $currentuser->getID() == 0 ) { ?>
            <li id="menu_login"><a href="login.php">Log In</a></li>
          <?php } else { ?>
            <li id="menu_logout"><a href="logout.php">Log Out</a></li>
          <?php } ?>
        </ul>
