batch delete

http://star1530.pixnet.net/blog/post/347924063-%E5%88%A9%E7%94%A8bat%E6%AA%94%E6%8E%92%E7%A8%8B%E8%87%AA%E5%8B%95%E5%88%AA%E9%99%A4%E6%AA%94%E6%A1%88