public static string MD5(string Input, bool Half)    //加密是16位還是32位；如果為true為16位
        {
            string output = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(Input, "MD5").ToLower();
            if (Half) output = output.Substring(8, 16);
            return output;
        }

        public static string MD5(string Input)
        {
            return MD5(Input, true);
        }