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 = 100;// 左侧广告距离页首高度 
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 = 100;// 右侧广告距离页首高度 
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/def1.jpg border='0'></div>" 
+"<div id=AdLayer2 style='position: absolute;visibility:hidden;z-index:1'><img src=images/def2.jpg border='0'></div>"); 
initEcAd() 

// JavaScript Document