var SlideList = new Class({
    initialize: function(menu, options) {
        this.setOptions(this.getOptions(), options);

        this.menu = $(menu), this.current = this.menu.getElement('li.current');

        this.menu.getElements('li').each(function(item) {
            item.addEvent('mouseover', function() { this.moveBg(item); } .bind(this));
            item.addEvent('mouseout', function() { this.moveBg(this.current); } .bind(this));
            item.addEvent('click', function(event) { this.clickItem(event, item); } .bind(this));
        } .bind(this));

        this.back = new Element('li').addClass('background').adopt(new Element('div').addClass('left')).injectInside(this.menu);
        this.back.fx = this.back.effects(this.options);
        if (this.current) this.setCurrent(this.current);
    },

    setCurrent: function(el, effect) {
        this.back.setStyles({ left: (el.offsetLeft) + 'px', width: (el.offsetWidth) + 'px' });
        (effect) ? this.back.effect('opacity').set(0).start(1) : this.back.setOpacity(1);
        this.current = el;
    },

    getOptions: function() {
        return {
            transition: Fx.Transitions.sineInOut,
            duration: 500, wait: false,
            onClick: Class.empty
        };
    },

    clickItem: function(event, item) {
        if (!this.current) this.setCurrent(item, true);
        this.current = item;
        this.options.onClick(new Event(event), item);
    },

    moveBg: function(to) {
        if (!this.current) return;
        this.back.fx.custom({
            left: [this.back.offsetLeft, to.offsetLeft],
            width: [this.back.offsetWidth, to.offsetWidth]
        });
    }
});

SlideList.implement(new Options);



window.addEvent('domready',
function() {
    new SlideList($E('ul', 'fancymenu'), { transition: Fx.Transitions.backOut, duration: 700, onClick: function(ev, item) { ev.stop(); } });
});

function SetCurrentMenu(menuID) {
    document.getElementById(menuID).setAttribute('class', 'current');
    document.getElementById(menuID).setAttribute('className', 'current');
}