如何在网页的两边用javascript做出条幅广告

Question

楼住要记得给点分我呀<SCRIPT LANGUAGE="JavaScript">
<!--function initEcAd() {
document.all.AdLayer1.style.posTop = -200;
document.all.AdLayer1.style.visibility = 'visible'
document.all.AdLayer2.style.posTop = -200;
document.all.AdLayer2.style.visibility = 'visible'
MoveLeftLayer('AdLayer1');
MoveRightLayer('AdLayer2');
}
function MoveLeftLayer(layerName) {
var x = 5;
var y = 340;
var diff = (document.body.scrollTop + y - document.all.AdLayer1.style.posTop)*.40;
var y = document.body.scrollTop + y - diff;
eval("document.all." + layerName + ".style.posTop = parseInt(y)");
eval("document.all." + layerName + ".style.posLeft = x");
setTimeout("MoveLeftLayer('AdLayer1');", 20);
}
function MoveRightLayer(layerName) {
var x = 5;
var y = 340;
var diff = (document.body.scrollTop + y - document.all.AdLayer2.style.posTop)*.40;
var y = document.body.scrollTop + y - diff;
eval("document.all." + layerName + ".style.posTop = y");
eval("document.all." + layerName + ".style.posRight = x");
setTimeout("MoveRightLayer('AdLayer2');", 20);
}document.write("<div id=AdLayer1 style='position: absolute;visibility:hidden;z-index:1'><img src=images/banner/job.gif></div>"
 +"<div id=AdLayer2 style='position: absolute;visibility:hidden;z-index:1'><img src=images/banner/zyeb.gif></div>");
initEcAd()
//-->
</SCRIPT>