C#

public static bool ValidateServerCertificate(
      object sender,
      X509Certificate certificate,
      X509Chain chain,
      SslPolicyErrors sslPolicyErrors)
    {
        return true;       
    }

ServicePointManager.ServerCertificateValidationCallback += new System.Net.Security.RemoteCertificateValidationCallback(ValidateServerCertificate);
CookieContainer c = new CookieContainer();

reqLogin = (HttpWebRequest)WebRequest.Create(url);
reqLogin.Method = "POST";
reqLogin.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.3)     Gecko/2008092417 Firefox/3.0.3 (.NET CLR 3.5.30729)";

reqLogin.ContentType = "application/x-www-form-urlencoded";
reqLogin.KeepAlive = true;
reqLogin.CookieContainer = new CookieContainer();
reqLogin.CookieContainer = c;
//reqLogin.CookieContainer.Add(col1);
reqLogin.AllowAutoRedirect = true;
reqLogin.UseDefaultCredentials = true;
reqLogin.Timeout = 5000;

using (StreamWriter sendingData = new
    StreamWriter(reqLogin.GetRequestStream()))
{
    sendingData.Write(postMessage);
    sendingData.Flush();
    sendingData.Close();
}

resLogin = (HttpWebResponse)reqLogin.GetResponse();