http://www.go-gddq.com/html/QiTa-ZongHe_tx/2013-01/992622.htm
http://blog.csdn.net/niuxuheng/article/details/39345241
http://www.cnblogs.com/fyhui/archive/2012/05/03/2480305.html
http://www.cnblogs.com/fyhui/archive/2012/05/01/2478093.html