jquery防淘宝返回顶部实现方法

$(document).ready(function() {
$('a[href*=#]').click(function() {
if (location.pathname.replace(/^//,'') == this.pathname.replace(/^//,'')
&& location.hostname == this.hostname) {
var $target = $(this.hash);
$target = $target.length && $target
|| $('[name=' + this.hash.slice(1) +']');
if ($target.length) {
var targetoffset = $target.offset().top;
$('html,body')
.animate({scrolltop: targetoffset}, 900);
return false;
}
}
});
// how to use
// place this where you want to scroll to
<a name=top></a>
// the link
<a href="#top">go to top</a>
});