http://www.cnblogs.com/god_bless_you/archive/2010/05/20/1740296.html
http://www.cnblogs.com/god_bless_you/archive/2010/05/20/1740307.html
http://www.cnblogs.com/god_bless_you/archive/2010/05/20/1740311.html
http://blog.csdn.net/crave_shy/article/details/21157955
