css-进度条

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script language="javascript" type="text/javascript">
i=0;
function startbar(){
showbar=setInterval("setbar()",500);
}
function setbar(){
i+=5;
if(i>=100){
clearInterval(showbar);
}
document.getElementById("bar").style.width=i+"%";
document.getElementById("bar").innerHTML=i+"%";
}
</script>
<link type="text/css" href="demo.css" rel="stylesheet"/>
<title>Untitled Document</title>
</head>
<body onload="startbar();">
<div >
<strong >30%</strong>
</div>
</body>
</html>
#loadbar{
width:280px;
background-color:#000;
border:1px solid #000;
}
#bar{
display:block;
font-family:Arial, Helvetica, sans-serif;
font-size:12px;
background-color:#00d0ff;
text-align:center;
}