<html>
<head>
<title>HTML DOM Objects</title>
</head>
<body>
<p>点击按钮获取文档title标签的文本内容：</p>
<p id="demo"></p>
<button onclick="myFunction()">点我</button>
<script>
function myFunction()
{
var x = document.getElementsByTagName("TITLE")[0].text;
document.getElementById("demo").innerHTML = x;
};
</script>
</body>
</html>