$(document).ready(function(){
    var aHeights = new Array();
    $('div#mainmenu ul.nav > li ul.mainmenu').each(function() {
        aHeights[$(this).parent().attr('id')] = $(this).height();
    });
        
    $('div#mainmenu ul.nav').addClass('ready');

    $('div#mainmenu ul.nav > li').hover(
        function() {
            $(this).find('ul.mainmenu').animate({
                'height': aHeights[$(this).find('div').attr('id')]
            }, 
            {
                duration: 'slow',
                easing: 'quadEaseOut',
                queue: false
            });
        }, 
        function() {
            $(this).find('ul.mainmenu').animate({
                'height': 0
            }, 
            {
                duration: 'slow',
                easing: 'quadEaseOut',
                queue: false
            });
        }
    );
    
});