MVC4重复提交

http://blog.sina.com.cn/s/blog_712ff52a0101f38r.html

http://blog.csdn.net/litao2/article/details/8681332

 performance

http://blogs.msdn.com/b/rickandy/archive/2011/05/21/using-cdns-to-improve-web-site-performance.aspx

 http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html