Jquery: everything works, but my function wont fire

Everything works just fine, but when I remove

{queue:false, duration: 800, easing: 'easeInOutQuart'} 

from

$(".chapters_list").slideDown(

with a 500, it stops working. So if I don't want easing in my script, it will work fine, when I insert easing into t开发者_JAVA技巧he top function, like is shown below, it stops working. Why wont it allow me to have easing?

$('.article_book_title').click(function () {
    if ($(".chapters_list").is(":hidden")) {
        $(".chapters_list").slideDown({queue:false, duration: 800, easing: 'easeInOutQuart'}, function () {
        doSlide($('UL.chapters_list li:first'))
        });   
} else {
$(".chapters_list").slideUp({queue:false, duration: 800, easing: 'easeInOutQuart'});
}
});


function doSlide(current) {
    $(current).animate({
        backgroundColor:'#d6f4aa', color:'#eee'
    },40, function() {
        $(this).animate({backgroundColor:'#252525', color:'#fff'}, 500)
            doSlide($(current).next('li'));
        });

}

The shortcut methods like slideUp dont take an object config as an argument.. they take the duration and the call back. If you want more advance options you have to use the animate method.

slideUp API