1.http://www.cnblogs.com/Ewin/archive/2009/10/05/1578322.html
2.http://zhidao.baidu.com/link?url=T1KpT4fUPQPRioPc0eMpvNhjJ46eOy8N2yaQmhUuWz-IPdulKrl2o5KWJmeXZbzEk1AAn1BCV8DVQ95PCfCciqWYWW197Eie6drzZDgcHzO