http://wenku.baidu.com/link?url=o9Xacr4tYocCPhivayRQXfIc9kOZeWBwPn2FZfeF19P4-8YX5CMXs74WB-Y8t0S96cb8x7cNpL-2A4OKd3wiet89u0aYszge7pn4U_WfJUq
http://www.cnblogs.com/daxnet/archive/2008/11/08/1687014.html
