how send sms using api

protected void btnSend_Click(objectsender, EventArgs e)

    {

       

        HttpWebRequestrequest = (HttpWebRequest)WebRequest.Create("http://www.sitename.in/pushsms.php?UserName=abc&Password=xyz&Type=Individual&To="+ txtMobileNo.Text + "&Mask=S H A M &Message=" + txtMessage.Text) asHttpWebRequest;

        HttpWebResponseresponse = (HttpWebResponse)request.GetResponse();

        StreamreceiveStream = response.GetResponseStream();

        Encoding encode = System.Text.Encoding.GetEncoding("utf-8");

        StreamReaderreadStream = new StreamReader(receiveStream, encode);

        stringa = readStream.ReadToEnd().ToString();

        response.Close();

        readStream.Close();

    }

    #region characters as byte array

   

    public string UTF8ByteArrayToString(byte[] characters)

    {

        UTF8Encoding encoding = new UTF8Encoding();

        stringconstructedString = encoding.GetString(characters);

        returnconstructedString;

    }

    #endregion