<html><body><h1>Event timeStamp</h1><p>单击该按钮可获取从该文档加载到单击该按钮的毫秒数。</p><button onclick="myFunction(event)">点击我!</button><p>此文档加载后的时间：<span id="demo"></span></p><script>function myFunction(event) { var n = event.timeStamp; document.getElementById("demo").innerHTML = n;}</script></body></html>