/********************************
* Prototype extensions
********************************/


// Add a mouse wheel event
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
    }
});