browser scroll bar smoothing 平滑

gistfile1.as

// http://bassta.bg/2013/05/smooth-page-scrolling-with-tweenmax/

$(function(){	

        var $window = $(window);
	var scrollTime = 1.2;
	var scrollDistance = 170;

	$window.on("mousewheel DOMMouseScroll", function(event){

		event.preventDefault();	

		var delta = event.originalEvent.wheelDelta/120 || -event.originalEvent.detail/3;
		var scrollTop = $window.scrollTop();
		var finalScroll = scrollTop - parseInt(delta*scrollDistance);

		TweenMax.to($window, scrollTime, {
			scrollTo : { y: finalScroll, autoKill:true },
				ease: Power1.easeOut,
				overwrite: 5							
			});

	});
});

gistfile2.html

<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script src="http://cdnjs.cloudflare.com/ajax/libs/gsap/latest/TweenMax.min.js"></script>
<script src="http://cdnjs.cloudflare.com/ajax/libs/gsap/latest/plugins/ScrollToPlugin.min.js"></script>