加一个延迟，窗口就不会关这么快了啦
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>close()</title>
<script type="text/javascript">
var mywin=window.open("http://www.imooc.com");
setTimeout(function(){mywin.open();}, 5000);
setTimeout(function(){mywin.close();}, 5000);
</script>
</head>
<body>
</body>
</html>
