在浏览器窗口外移动的图片

<SCRIPT>
var imagepath="images/Angell.gif"
var imagewidth=80powered by 25175.net
var imageheight=80
var speed=3;
var imageclick="http://www.25175.com" 
var hideafter=0
var isie=0;
if(window.navigator.appName=="Microsoft Internet Explorer"&&window.navigator.appVersion.substring(window.navigator.appVersion.indexOf("MSIE")+5,window.navigator.appVersion.indexOf("MSIE")+8)>=5.5) {
isie=1;
}
else {
isie=0;
}
if(isie){
var preloadit=new Image()
preloadit.src=../../../imagepath
}
function pop() {
if(isie) {
x=x+dx;y=y+dy;
oPopup.show(x, y, imagewidth, imageheight);
if(x+imagewidth+5>screen.width) dx=-dx;
if(y+imageheight+5>screen.height) dy=-dy;
if(x<0) dx=-dx;
if(y<0) dy=-dy;
startani=setTimeout("pop();",50);
}
}
function dismisspopup(){
clearTimeout(startani)
oPopup.hide()
}
function dowhat(){
if (imageclick=="dismiss")
dismisspopup()
else
window.open(imageclick);
}
if(isie) {
var x=0,y=0,dx=speed,dy=speed;
var oPopup = window.createPopup();
var oPopupBody = oPopup.document.body;
oPopupBody.style.cursor="hand"
oPopupBody.innerHTML = '<IMG SRC="'+preloadit.src+'">';
oPopup.document.body.onmouseover=new Function("clearTimeout(startani)")
oPopup.document.body.onmouseout=pop
oPopup.document.body.onclick=dowhat
pop();
if (hideafter>0)
setTimeout("dismisspopup()",hideafter*1000)
}
</SCRIPT>