Hit a snag with simple accordion menu

Hit a snag with simple accordion menu

I've put together a rather simple accordion menu but am having trouble getting the visible menus to "slideUp" when another sibling <li> is selected.  The initial "hide" and "slideToggle" function works just fine.

I'm using this format for the menu:

<div class="accordion">
      <ul>
            <li><a href="#">NAV LINK #1</a>
                  <ul>
                        <li><a href="#">second level link #1</a></li>
                        <li><a href="#">second level link #1</a></li>
                        <li><a href="#">second level link #1</a></li>
                        <li><a href="#">second level link #1</a></li>
                  </ul>
            </li>
            <li>NAV LINK #2...

  1. <script type="text/javascript">
  2. $(document).ready(function() {
  3.  $('div.accordion> ul ul').hide();
  4.  $('div.accordion> ul li a').click(function() {
  5.    $(this).next('ul').slideToggle('fast')
  6.    .siblings('ul:visible').slideUp('fast');
  7.  });
  8. });
  9. </script>


Any help would be GREATLY appreciated!

Thanks!
Matt