function init_Ad_Left() {
document.all.AdLeftLayer.style.posTop = -200;
//设置onLoad事件激发以后，广告层相对于固定后的y方向位置
document.all.AdLeftLayer.style.visibility = 'visible'//设置层为可见
MoveLeftLayer('AdLeftLayer');//调用函数MoveLayer()
}
function MoveLeftLayer(layerName) 
{
var x =-1000;//浮动广告层固定于浏览器的x方向位置
var y = 5;//浮动广告层固定于浏览器的y方向位置
var diff = (document.documentElement.scrollTop + y - document.all.AdLeftLayer.style.posTop)*.90;
var y = document.documentElement.scrollTop + y - diff;
eval("document.all." + layerName + ".style.posTop = y");
eval("document.all." + layerName + ".style.posright = x");//移动广告层
setTimeout("MoveLeftLayer('AdLeftLayer');", 0);//设置20毫秒后再调用函数MoveLayer()
}