private string SendSMS()
{

  string URL = "http://ws.rahatsms.com/webservices/wsurl/url/send";

  string Username = "YOUR-USERNAME";

  string Password = "YOUR-PASSWORD";

  int RequestTimeout = 30000;

  string Text = "YOUR-TEXT";

  string Recipient = "RECIPIENT(s)";

  string Channel = "YOUR-CHANNEL";

  string parameters =
                 string.Format("UserName={0}&Password={1}&Text={2}&To={3}&From={4}",Username,Password,Text,Recipient,Channel);

  try
  {
      URL = String.Concat(URL.ToString(), "?", parameters.ToString());
      System.Net.WebProxy proxyObject = new
      System.Net.WebProxy();
      System.Net.WebRequest request = System.Net.WebRequest.Create(URL);
      request.Timeout = (int)RequestTimeout;
      request.Proxy = proxyObject;
      request.Method = "POST";
      request.ContentType = "application/x-www-form-urlencoded";
      System.IO.StreamWriter sw = new
      System.IO.StreamWriter(request.GetRequestStream());
      sw.Write(request);
      sw.Close();
      System.Net.WebResponse objResponse = request.GetResponse();
      System.IO.StreamReader sr = new
      System.IO.StreamReader(objResponse.GetResponseStream());
      string result = sr.ReadToEnd();
      sr.Close();
      return result;
  }
  catch (Exception ex)
  {
      return ex.Message;
  }
                    

}