点击按钮导航条滚动在animate无法使用时的替代方法。

var fnScrollTo = function(target) {
	var curLeft = middleList.scrollLeft();
	var dur = 100;
	var index = 0;

	var interval = window.setInterval(function() {
		var relative = target - curLeft;
		var to = relative / dur *index + curLeft;
			
		index++;
		middleList.scrollLeft(to);
			
		if (index >= dur) {
			window.clearInterval(interval);
		}
	}, 3);
}