/*
 * Orginal: http://adomas.org/javascript-mouse-wheel/
 * prototype extension by "Frank Monnerjahn" <themonnie@gmail.com>
 */
Object.extend(Event, {
	wheel:function (event){
		var delta = 0;
		if (!event) event = window.event;
		if (event.wheelDelta) {
			delta = event.wheelDelta/120; 
			if (window.opera) delta = -delta;
		} else if (event.detail) { delta = -event.detail/3;	}
		return Math.round(delta); //Safari Round
	}
});
/*
 * enf of extension 
 */