<html>
<body>
<p>点击按钮创建 PROGRESS 元素并设置进度 "100"，当前为 "22"。</p>
<button onclick="myFunction()">点我</button>
<script>
function myFunction()
{
var x = document.createElement("PROGRESS");
x.setAttribute("value", "22");
x.setAttribute("max", "100");
document.body.appendChild(x);
}
</script>
</body>
</html>