jQuery实现的图片分组切换焦点图插件

            });
            //下一组
            next.click(function () {
                num++;
                if (num >= $number) { num = 0 }
                var leftdis = -2 * $w * num;
                $(‘.scroll ul’).stop().animate({ left: leftdis });
            });
            //上一组
            pre.click(function () {
                num–;
                if (num < 0) { num = $number – 1 }
                var rightdis = -2 * $w * num;
                $(‘.scroll ul’).stop().animate({ left: rightdis });
            });
        });