<div id="img" style="position:absolute;">
<a href="http://www.site321.cn" target="_blank">
<img src="http://www.site321.cn/advs/1184603169.jpg" border="0"></a>
</div>

<SCRIPT LANGUAGE="JavaScript">
<!--
var xPos = document.body.clientWidth;
var yPos = document.body.clientHeight;
var step = 1;
var delay = 10;
var Width = 0;
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 = (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 www_site321_cn() {
img.visibility = "visible";
interval = setInterval('changePos()', delay);
}
www_site321_cn();
-->
</script>

红色字体：图片连接地址；
蓝色字体：图片存放地址；
绿色字体：图片移动速度（值越小移动越快）