<html>
<body>
<h3>访问 DETAILS 元素实例演示</h3>
<details id="myDetails">
一些额外信息...
</details>
<p>点击 "尝试一下" 按钮显示额外信息。</p>
<button onclick="myFunction()">尝试一下</button>
<script>
function myFunction()
{
var x = document.getElementById("myDetails");
x.open=true;
}
</script>
</body>
</html>