adTime=17; //关闭窗口等待的时间 

chanceAd=1; 

var ns=(document.layers); 

var ie=(document.all); 

var w3=(document.getElementById && !ie); 

adCount=0; 

function initAd(){ 

if(!ns && !ie && !w3) return; 

if(ie) adDiv=eval('document.all.sponsorAdDiv.style'); 

else if(ns) adDiv=eval('document.layers["sponsorAdDiv"]'); 

else if(w3) adDiv=eval('document.getElementById("sponsorAdDiv").style'); 

randAd=Math.ceil(Math.random()*chanceAd); 

if (ie||w3) 

adDiv.visibility="visible"; 

else 

adDiv.visibility ="show"; 

if(randAd==1) showAd(); 

} 

function showAd(){ 

if(adCount<adTime*10){adCount+=1; 

//if (ie){documentWidth =document.body.offsetWidth/2+document.body.scrollLeft-20; 

//documentHeight =document.body.offsetHeight/2+document.body.scrollTop-20;} 

//else if (ns){documentWidth=window.innerWidth/2+window.pageXOffset-20; 

//documentHeight=window.innerHeight/2+window.pageYOffset-20;} 

//else if (w3){documentWidth=self.innerWidth/2+window.pageXOffset-20; 

//documentHeight=self.innerHeight/2+window.pageYOffset-20;} 

//adDiv.left=documentWidth-200;adDiv.top =documentHeight-200; 

setTimeout("showAd()",100);}else closeAd(); 

} 

function closeAd(){ 

if (ie||w3) 

adDiv.display="none"; 

else 

adDiv.visibility ="hide"; 

} 

onload=initAd;