javascript|定时|页面
<HTML>
<HEAD>
<META http-equiv='Content-Type' content='text/html; charset=gb2312'>
<TITLE>在页面上显示的一部分内容，在经过设定好的时间后会自动消失</TITLE>
</HEAD>
<BODY >
<SCRIPT LANGUAGE="JavaScript1.2">
adTime=10; // seconds ad reminder is shown
chanceAd=1; // ad will be shown 1 in X times (put 1 for everytime)
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;
//End-->
</script>
<div id="sponsorAdDiv" bgcolor="#008000"><tr><td>
<table width="300" bgcolor="#F0FFF0"><tr><td align="center" valign="middle">
<p><b>网页教学网欢迎你的光临
请多提宝贵意见，谢谢
你的光临是对我们最大的支持.</b>
</p>
<p>(这个显示区将在几秒钟内自动关闭)
</td></tr></table></td></tr></table>
</div>
</BODY></HTML>
