Hi, I'm having problem in making this slider.

The slider would be something like

http://www.netzbewegung.com/

my main problem is that the auto centering of the slide when draged.

see my test site here.
http://myimagehost.zxq.net/slide_drag/

...
var x=$(window).width()-$('#slide-box').width();

    $('#slide-box ul').bind('drag',function( event ){
   
        $( this ).css({ left: event.offsetX-(x*0.5)});
     });
     
    $('#slide-box ul').bind('click', function(){
        var $win=$(window).width();
        var $i= $(this).position();
            $i=$i.left;
        if ($i>=0 || $i<0){
            $( this ).animate({ left: event.offsetX-(x*0.5)},500);
        }
       
    })

I really need help here. please some one answer.
thanks in advance!