$(document).ready( function() {
    $('div#nav li > ul').hide();    //hide all nested ul's
    $('div#nav li > ul li a[class=current]').parents('ul').show().prev('a').addClass('accordionExpanded');  //show the ul if it has a current link in it (current page/section should be shown expanded)
    $('div#nav li:has(ul)').addClass('accordion');  //so we can style plus/minus icons
    $('div#nav li:has(ul) > a').click(function() {
        $(this).toggleClass('accordionExpanded'); //for CSS bgimage, but only on first a (sub li>a's don't need the class)
        $(this).next('ul').slideToggle('fast');
        $(this).parent().siblings('li').children('ul:visible').slideUp('fast')
            .parent('li').find('a').removeClass('accordionExpanded');
        return false;
    });
});