Jquery滑块左上方和右上方

Question

大家好我想在这个现有脚本中添加top和bottom，我尝试根据需要修改javascript，但是我无法看到顶部和底部的箭头。我添加了以下img标签

<div class="next-anchor">
    <img src="~/images/large_down.png">
</div>

if (index === 0) {
    $('.horizon-prev').hide();
    $('.horizon-next').show();
    $('.next-anchor').show();
} else if (index === $.fn.horizon.defaults.limit - 1) {
    $('.horizon-prev').show();
    $('.horizon-next').hide();
    $('.next-anchor').show();
} else {
    $('.horizon-next').show();
    $('.horizon-prev').show();
    $('.next-anchor').show();
}

http://www.jqueryscript.net/demo/Creating-A-Horizontal-Scrolling-Website-with-jQuery-horizonScroll-js/