<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>弹性返回顶部JS代码</title>
<script type="text/javascript">
function goTopEx() {
var obj = document.getElementById("goTopBtn");
function getScrollTop() {
return document.documentElement.scrollTop + document.body.scrollTop;
}
function setScrollTop(value) {
if (document.documentElement.scrollTop) {
document.documentElement.scrollTop = value;
} else {
document.body.scrollTop = value;
}
}
window.onscroll = function() {
getScrollTop() > 0 ? obj.style.display = "": obj.style.display = "none";
}
obj.onclick = function() {
var goTop = setInterval(scrollMove, 10);
function scrollMove() {
setScrollTop(getScrollTop() / 1.1);
if (getScrollTop() < 1) clearInterval(goTop);
}
}
}
</script>
<style>
BODY {
HEIGHT: 3600px;
}
#goTopBtn {
POSITION: fixed; TEXT-ALIGN: center; LINE-HEIGHT: 30px; WIDTH: 30px; BOTTOM: 35px; HEIGHT: 33px; FONT-SIZE: 12px; CURSOR: pointer; RIGHT: 0px; _position: absolute; _right: auto
}
</style>
</head>
<body style="text-align:center">
<div style="display: none" id="goTopBtn"><img border=0 src="/${res}/img/go_to_top.png"></div>
<script type=text/javascript>goTopEx();</script>
<br /><br /><br /><br /><br /><br /><br />
<p></p>
<p><p>超出首屏范围，即会出现TOP按钮，否则自动隐藏。<br />
</p></p>
<p></p>
</body>
</html>
