Push notification for android from asp.net webservice

using System;
using System.IO;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Text;

namespace ENSource.Infrastructure
{
    public static class AndroidGCM
    {
        public static string SendGCMNotification(string apiKey, string postData, string postDataContentType = "application/json")
        {
            //Delegate Modeling to Validate Server Certificate
            ServicePointManager.ServerCertificateValidationCallback += new RemoteCertificateValidationCallback(ValidateServerCertificate);           
            
            //MESSAGE CONTENT
            byte[] byteArray = Encoding.UTF8.GetBytes(postData);
            
            //CREATE REQUEST
            HttpWebRequest Request = (HttpWebRequest)WebRequest.Create("https://android.googleapis.com/gcm/send");
            Request.Method = "POST";
            Request.KeepAlive = false;
            Request.ContentType = postDataContentType;
            Request.Headers.Add(HttpRequestHeader.Authorization, string.Format("key={0}", apiKey));
            Request.ContentLength = byteArray.Length;

            //Create Stream to Write Byte Array
            Stream dataStream = Request.GetRequestStream();
            dataStream.Write(byteArray, 0, byteArray.Length);
            dataStream.Close();

            try
            {
                //Post a Message
                WebResponse Response = Request.GetResponse();

                //Check the response status
                HttpStatusCode ResponseCode = ((HttpWebResponse)Response).StatusCode;

                string errorMessage = string.Empty;
                if (ResponseCode.Equals(HttpStatusCode.Unauthorized) || ResponseCode.Equals(HttpStatusCode.Forbidden))
                {
                    errorMessage = "Unauthorized - need new token";

                }
                else if (!ResponseCode.Equals(HttpStatusCode.OK))
                {
                    errorMessage = "Response from web service isn't OK";
                }

                StreamReader Reader = new StreamReader(Response.GetResponseStream());
                string responseLine = Reader.ReadToEnd();
                Reader.Close();

                return responseLine;
            }
            catch (Exception e)
            {
                return "error";
            }            
        }

        public static bool ValidateServerCertificate(

                                                   object sender,

                                                  X509Certificate certificate,

                                                  X509Chain chain,

                                                   SslPolicyErrors sslPolicyErrors)
        {

            return true;

        }
    }    
}

/*

GCM gcm = new GCM();

            var applicationID = "******wdVY8xs";
            string deviceId = "A*****EAsEDth";
            string message = "hey ,some text message";
            string tickerText = "example test GCM";
            string contentTitle = "content title GCM";
            string postData =
            "{ \"registration_ids\": [ \"" + deviceId + "\" ], " +
              "\"data\": {\"tickerText\":\"" + tickerText + "\", " +
                         "\"contentTitle\":\"" + contentTitle + "\", " +
                         "\"message\": \"" + message + "\"}}";

            var X = gcm.SendGCMNotification(applicationID, postData);
*/