jquery配合css简单实现返回顶部效果

CSS：

.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

(function() { 
var $backToTopTxt = "返回顶部", $backToTopEle = $('<div class="backToTop"></div>').appendTo($("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(); }); })();：