window.addEvent('load', function() {
    var list = $$('div#user3 li');
    list.each(function(element) {
        if ($(element).getElement('ul')) {
            el = $(element).getElement('ul')
            var fx = new Fx.Styles(el, {duration:10, wait:false, transition: Fx.Transitions.linear});
            el.setStyle('opacity', 0);
            element.addEvent('mouseenter', function(){                
                fx.start({'opacity': 1});
            });
            element.addEvent('mouseleave', function(){
                fx.start({'opacity': 0});
            });
        }     
    });
});