HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.KeepAlive = false;
            req.Method = "POST";
            req.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
            req.Credentials = CredentialCache.DefaultCredentials;
            req.ContentType = "application/x-form-www-urlencoded";
            Encoding encode = new UTF8Encoding();

            byte[] b = encode.GetBytes(string.Format("Content={0}&Type={1}&StartDate={2}&EndDate={3}", content, columnname.ToLower() == "macaddress" ? 1 : 0, DateTime.Now.AddDays(-1).Date.ToString("yyyy-MM-dd 00:00:00"), DateTime.Now.Date.ToString("yyyy-MM-dd 00:00:00")));
            req.ContentLength = b.Length;
            using (Stream stream = req.GetRequestStream())
            {
                stream.Write(b, 0, b.Length);
            }

            WebResponse res = req.GetResponse();
            StreamReader sr = new StreamReader(res.GetResponseStream(), encode);
            string result = sr.ReadToEnd();
            res.Close();
            sr.Close();