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,160);
		if (event.preventDefault) event.preventDefault();
		event.returnValue = false;
	}
}
if (window.addEventListener) {
	window.addEventListener('DOMMouseScroll',mouseWheel,false);
}
window.onmousewheel = document.onmousewheel = mouseWheel;