朱峰 知乎:用JAVA做一网页两边的广告

用JAVA做一网页两边的广告，如果就做一边的可以只要调用就能实现我想要的功能，但是如果我做两边的就出错了哦。这是怎么回事？？代码如下：
self.onError = null;

currentX = currentY = 0;

whichIt = null;

lastScrollX = 0; lastScrollY = 0;

NS = (document.layers) ? 1 : 0;

IE = (document.all) ? 1: 0;

<!-- STALKER CODE -->

function heartBeat(objectid) {

if(IE) { diffY = document.body.scrollTop; diffX = document.body.scrollLeft; }

if(NS) { diffY = self.pageYOffset; diffX = self.pageXOffset; }

if(diffY != lastScrollY) {

percent = .1 * (diffY - lastScrollY);

if(percent > 0) percent = Math.ceil(percent);

else percent = Math.floor(percent);

if(IE) {

objectid = objectid.split(";");

for (i = 0; i < objectid.length; i++) eval("document.all."+objectid[i]).style.pixelTop += percent;

}

if(NS) {

objectid = objectid.split(";");

for (i = 0; i < objectid.length; i++) eval("document."+objectid[i]).top += percent;

}

lastScrollY = lastScrollY + percent;

}

if(diffX != lastScrollX) {

percent = .1 * (diffX - lastScrollX);

if(percent > 0) percent = Math.ceil(percent);

else percent = Math.floor(percent);

if(IE) {

objectid = objectid.split(";");
for (i = 0; i < objectid.length; i++) eval("document.all."+objectid[i]).style.pixelLeft += percent;

}
if(NS) {
objectid = objectid.split(";");
for (i = 0; i < objectid.length; i++) eval("document."+objectid[i]).left += percent;
}
lastScrollX = lastScrollX + percent;
}
}

<!-- /STALKER CODE -->
if(NS || IE) action = window.setInterval("heartBeat('floater2')", 2);