function hookEvent(element, eventName, callback)
    {
        if (typeof(element) == "string")
            element = document.getElementById(element);
        if (element == null)
            return;
        if (element.addEventListener)
        {
            if (eventName == 'mousewheel')
                element.addEventListener('DOMMouseScroll', callback, false);
            element.addEventListener(eventName, callback, false);
        }
        else if (element.attachEvent())
            element.attachEvent("on" + eventName, callback);
    }

    function unhookEvent(element, eventName, callback)
    {
        if (typeof(element) == "string")
            element = document.getElementById(element);
        if (element == null)
            return;
        if (element.removeEventListener)
        {
            if (eventName == 'mousewheel')
                element.removeEventListener('DOMMouseScroll', callback, false);
            element.removeEventListener(eventName, callback, false);
        }
        else if (element.detachEvent)
            element.detachEvent("on" + eventName, callback);
    }

    function cancelEvent(e)
    {
        e = e ? e : window.event;
        if (e.stopPropagation)
            e.stopPropagation();
        if (e.preventDefault)
            e.preventDefault();
        e.cancelBubble = true;
        e.cancel = true;
        e.returnValue = false;
        return false;
    }