JavaScript监控浏览器关闭并发送后台请求的实现

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<html> 
<head> 
 <title> New Document </title> 
 <meta name="Generator" content="EditPlus"> 
 <meta name="Author" content=""> 
 <meta name="Keywords" content=""> 
 <meta name="Description" content=""> 
</head> 
  
<body> 
 <script type="text/javascript"> 
 window.onbeforeunload = onbeforeunload_handler;   
  window.onunload = onunload_handler;   
  function onbeforeunload_handler(){   
    var warning="确认关闭www.someabcd.com?";     
    //你的业务操作。。。。    
    return warning;   
  }   
     
  function onunload_handler(){   
    var warning="谢谢光临www.someabcd.com";  
    //你的业务操作。。。。  
    alert(warning);   
  }   
 </script> 
</body> 
</html>