浮动窗口 图片在页面动

<div id="img" style="position:absolute; left:35px; top:556px; width:120; height:172">
<img src="injob.jpg" width=100 height=100></img>
</div>

<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
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 = (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() {
img.visibility = "visible";
interval = setInterval('changePos()', delay);
}

start();

// End -->

</script>