smsboxDemo

 void SendSms(string number, string message)
    {
        var username = ConfigurationManager.AppSettings["SmsUsername"];
        var password = ConfigurationManager.AppSettings["SmsPassword"];
        var custId = ConfigurationManager.AppSettings["SmsCustomerId"];
        var senderName = ConfigurationManager.AppSettings["SmsSenderText"];

        HttpWebRequest req = (HttpWebRequest)WebRequest.Create("https://www.smsbox.com/SMSGateway/Services/Messaging.asmx/Http_SendSMS");
        req.Method = "POST";
        req.ContentType = "application/x-www-form-urlencoded";
        string postData = string.Format("username={0}&password={1}&customerId={2}&senderText={3}&messageBody={4}&recipientNumbers={5}&defDate=&isBlink=false&isFlash=false",
           username, password, custId, senderName, HttpUtility.UrlEncode( message), number);
        req.ContentLength = postData.Length;

        StreamWriter stOut = new
        StreamWriter(req.GetRequestStream(),
        System.Text.Encoding.ASCII);
        stOut.Write(postData);
        stOut.Close();
        string strResponse;
        StreamReader stIn = new StreamReader(req.GetResponse().GetResponseStream());
        strResponse = stIn.ReadToEnd();
        stIn.Close();

    }