页面中的滚动条定时自动下滚

 scrollBar();
    function scrollBar() {
        height = $('.layui-table-body').height();
        var number = 0;
        var length = 0;
        var time = setInterval(function () {
            number += 1;
            if (number == 12) {
                clearInterval(time);
                $('.layui-table-body').scrollTop('0');
            } else {
                length += height / 11;
                $('.layui-table-body').scrollTop(length);  //只有此处有区别
            }
        }, 1000);
    }

    setInterval(function () {
        scrollBar()
    }, 13000)