html运行实例（event_ondurationchange

代码示例：（标识：event_ondurationchange_dom）

<!DOCTYPE html> 
<html> 
<body> 

<p>本例使用 HTML DOM 将 "ondurationchange" 事件分配给 video 元素。</p>

<video controls id="myVideo">
  <source src="/static/demo/video/shanghai.mp4" type="video/mp4">
  Your browser does not support HTML5 video.
</video>

<script>
document.getElementById("myVideo").ondurationchange = function() {myFunction()};

function myFunction() {
  alert("The video duration has changed");
}
</script>

</body> 
</html>