漂浮窗(层)JS

<script language=JavaScript> 
<!-- Begin 
//more javascript from http://cfan.net.cn 
var xPos = 20; // 起始横向位置(从左算起，单位象素) 
var yPos = document.body.clientHeight; // 页面本身高度 
var step = 1; 
var delay = 30; // 速度，值越大速度越慢 
var height = 0; 
var Hoffset = 0; 
var Woffset = 0; 
var yon = 0; 
var xon = 0; 
var pause = true; 
var interval; 
dd.style.top = yPos; 
function changePos() { 
width = document.body.clientWidth; // 判断浏览器窗口的宽度 
height = document.body.clientHeight; // 判断浏览器窗口的高度 
Hoffset = dd.offsetHeight; 
Woffset = dd.offsetWidth; 
dd.style.left = xPos + document.body.scrollLeft; 
dd.style.top = yPos + document.body.scrollTop; 
if (yon) { 
yPos = yPos + step; 
} 
else { 
yPos = yPos - step; 
} 
if (yPos < 0) { 
yon = 1; 
yPos = 0; 
} 
if (yPos >= (height - Hoffset)) { 
yon = 0; 
yPos = (height - Hoffset); 
} 
if (xon) { 
xPos = xPos + step; 
} 
else { 
xPos = xPos - step; 
} 
if (xPos < 0) { 
xon = 1; 
xPos = 0; 
} 
if (xPos >= (width - Woffset)) { 
xon = 0; 
xPos = (width - Woffset); 
} 
} 
function start() { 
dd.visibility = "visible"; 
interval = setInterval('changePos()', delay); 
} 
function pause_resume() { 
if(pause) {clearInterval(interval);pause = false;} 
else {interval = setInterval('changePos()',delay);pause = true;} 
} 
start(); 
// End --> 
</script>

<div id=dd style="Z-INDEX: 1; WIDTH: 100px; POSITION: absolute; HEIGHT: 132px">
<a href=# target="_blank">
<img src="images/xxx.jpg" width="248" height="100" border="0" alt="随便一个图片" />
</a>
</div>