网页中加载浮动的广告

 <SCRIPT language=javascript>
<!--
var isDOM = (document.getElementById ? true : false);
var isIE4 = ((document.all && !isDOM) ? true : false);
var isNS4 = (document.layers ? true : false);
var isNS = navigator.appName == "Netscape";

function getRef(id) {
  if (isDOM) return document.getElementById(id);
  if (isIE4) return document.all[id];
  if (isNS4) return document.layers[id];
}

function heartBeat() {
  var yMenuFrom, yMenuTo, yOffset, timeoutNextCheck, nHeight;

  nHeight =348;

  if (isDOM) {
    yMenuFrom = parseInt (divMenu.style.top,0);
    yMenuTo = (isNS ? window.pageYOffset+nHeight : document.body.scrollTop+nHeight);
  }

  timeoutNextCheck = 500;

  if (yMenuFrom != yMenuTo) {
    yOffset = Math.ceil(Math.abs(yMenuTo - yMenuFrom)/20);
   
    if (yMenuTo < yMenuFrom) yOffset = -yOffset;

 if (isNS4) divMenu.top += yOffset;
    else if (isDOM) {
  if((parseInt (divMenu.style.top,0) + yOffset)>=348){
   divMenu.style.top = parseInt (divMenu.style.top,0) + yOffset;
  }else{
   divMenu.style.top = 348;
  }
 }

//    document.getElementById("_spider").style.height = parseInt(divMenu.style.top,0)-340;
    timeoutNextCheck = 10;
  }
  setTimeout ("heartBeat()", timeoutNextCheck);
}

function activate_quick() {
  divMenu = getRef('floater');
  heartBeat();
}
//-->
</SCRIPT>

注：必须加载在代码最上方