http://blog.csdn.net/nellson/archive/2010/02/06/5293519.aspx
http://download.csdn.net/source/2735995
http://blog.csdn.net/ycs0501/archive/2008/12/30/3649624.aspx
http://www.cppblog.com/xieshuo/archive/2008/08/18/59205.html
