请参考:
http://blog.wenxuecity.com/blogview.php?date=201004&postID=12043
http://blog.wenxuecity.com/blogview.php?date=201004&postID=12136
http://blog.wenxuecity.com/blogview.php?date=201004&postID=12043
http://blog.wenxuecity.com/blogview.php?date=201004&postID=12136