<html>
<body>
下载进度条：
<progress id="myProgress" value="22" max="100">
</progress>
<p>点击按钮返回进度条 value 属性的值。</p>
<p id="demo"></p>
<button onclick="myFunction()">点我</button>
<script>
function myFunction()
{
var x = document.getElementById("myProgress").value;
document.getElementById("demo").innerHTML = x;
}
</script>
</body>
</html>