怎样在自己的网站里加入浮动广告

<div id="img" style="position:absolute;">
<img src="你图的路径" border="0">
</div>

<SCRIPT LANGUAGE="JavaScript">
<!--
var xPos = 20;
var yPos = document.body.clientHeight;
var step = 1;
var delay = 30;
var height = 0;
var Hoffset = 0;
var Woffset = 0;
var yon = 0;
var xon = 0;
var pause = true;
var interval;
img.style.top = yPos;
function changePos() {
width = document.body.clientWidth;
height = document.body.clientHeight;
Hoffset = img.offsetHeight;
Woffset = img.offsetWidth;
img.style.left = xPos + document.body.scrollLeft;
img.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 = (he