<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>进度条</title>
</head>
<body>
<progress value="0" max="100" id="pro"></progress>
<script>
var t = 0;
var pro = document.getElementById('pro');
function jindu()
{
var v = pro.value;
if(v<100){
pro.value+=20;
}else
clearInterval(t);
}
t=setInterval(jindu,100)
</script>
</body>
</html>