<html>
<body>
<details id="myDetails" open>
<summary>Copyright 1999-2014.</summary>
<p> - by Refsnes Data. All Rights Reserved.</p>
<p>All content and graphics on this web site are the property of the company Refsnes Data.</p>
</details>
<p>点击 "尝试一下" 按钮来查看额外描述信息是否可见。</p>
<p id="demo"></p>
<button onclick="myFunction()">尝试一下</button>
<script>
function myFunction()
{
var x = document.getElementById("myDetails").open;
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>