CSS：

复制代码 代码如下:

.backToTop {

display: none;

width: 18px;

line-height: 1.2;

padding: 5px 0;

background-color: #000;

color: #fff;

font-size: 12px;

text-align: center;

position: fixed;

_position: absolute;

right: 10px;

bottom: 100px;

_bottom: "auto";

cursor: pointer;

opacity: .6;

filter: Alpha(opacity=60);

}

jQuery代码

复制代码 代码如下:

(function() {

var $backToTopTxt = "返回顶部", $backToTopEle = $('<div></div>').appendTo($("body"))

.text($backToTopTxt).attr("title", $backToTopTxt).click(function() {

$("html, body").animate({ scrollTop: 0 }, 120);

}), $backToTopFun = function() {

var st = $(document).scrollTop(), winh = $(window).height();

(st > 0)? $backToTopEle.show(): $backToTopEle.hide();

//IE6下的定位

if (!window.XMLHttpRequest) {

$backToTopEle.css("top", st + winh - 166);

}

};

$(window).bind("scroll", $backToTopFun);

$(function() { $backToTopFun(); }); })();：