<html>

<head>

<title>文字上下滚动</title>

</head>

<body>

<div id="TDiv" style="position: absolute;top: 50; color: #000000;font-size:20px;">

<p>文字上下滚动-JS代码</p></div>

<script language="JavaScript">

down=true;

function act(yp,yk,yx){

ob=document.all("TDiv");

ob.style.posTop=yp;

if (yp<=yx) down=true;

if (yp>=yk) down=false;

if (down){step=4;}

else{step=-4;}

setTimeout('act('+(yp+step)+','+yk+','+yx+')', 35);

}

function activity(){

ob=document.all("TDiv");

if (ob.style.posTop<=50){

var hei=document.body.clientHeight;

act(50,hei-100,50)

}

}

activity();

</script>

</body>

</html>