function mouseScroll(delta,step) {
		if (delta < 0) {
			window.scrollBy(step,0);
		} else {
			window.scrollBy(-step,0);
		}
	}

	function mouseWheel(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;
		}
		if (delta) {
			mouseScroll(delta,150);
			if (event.preventDefault) event.preventDefault();
			event.returnValue = false;
		}
	}

	if (window.addEventListener) {
		window.addEventListener('DOMMouseScroll',mouseWheel,false);
	}
	window.onmousewheel = document.onmousewheel = mouseWheel;