JavaScript悬浮窗口

<%-- 悬浮窗口开始 --%>
<DIV id=img style="Z-INDEX: 1000; POSITION: absolute"
onMouseOver="stop()" onMouseOut="www_helpor_net() ">
<TABLE cellSpacing=0 cellPadding=0 border=0>
<TR>
<TD align="right">
<A style="CURSOR: hand" onclick=closepiao()><b>关闭</b> </A>
</TD>
</TR>
<TR>
<TD id='obja'>
<a href="http://www.sohu.com/"> <IMG id=obj src="images/ad.jpg" border=0></a>
</TD>
</TR>
</TABLE>
</DIV>
<%-- 悬浮窗口结束 --%>

<%-- 悬浮窗口开始 --%>
<SCRIPT language=JavaScript>

var xPos = 20;
var yPos = document.body.clientHeight;
var step = 2;
var delay = 60;
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 closepiao()
{
document.all("img").style.display = "none";
}

function stop()
{
    clearInterval(interval);
}

function www_helpor_net() {
//closepiao();//注释后显示飘
img.visibility = "visible";
interval = setInterval('changePos()', delay);
}
www_helpor_net();
</SCRIPT>
<%-- 悬浮窗口结束 --%>