jquery返回页面顶部

1.样式设置

#toTop {       /*选中的背景图片的大小*/    width: 54px;    height: 54px;    display: none;/*刚开始不显示*/    position: fixed;    right: 25px;/*距离右边大小值*/    bottom: 45px;/*距离底部大小值*/       /*选定图片区域*/    background-image: url(images/qqbg_1.5.5.png);    background-repeat: no-repeat;    background-position: -700px -110px;    opacity: 0.3; /*透明度*/}#toTop:hover {    opacity: 1;/*悬停时不透明*/    filter: alpha(opacity = 100);}

 

2.js代码

<a href="#" target="_self" id="toTop" title="返回顶部" onclick="window.scrollTo(0,0);return false"></a><script type = "text/javascript">    function toTopHide(){        $(document).scrollTop()>400?                $("#toTop").show()                    :$("#toTop").hide();    }    $(window).scroll(function(){toTopHide()});</script>