How to call soap service

        public static void CallWebService()
        {
            
var _url = "https://www.dataaccess.com/webservicesserver/NumberConversion.wso"
            var _action= "";

            XmlDocument soapEnvelopeXml = CreateSoapEnvelope();
            HttpWebRequest webRequest = CreateWebRequest(_url, _action);

            using (Stream stm = webRequest.GetRequestStream())
            {
                using (StreamWriter stmw = new StreamWriter(stm))
                {
                    stmw.Write(soapEnvelopeXml);
                }
            }

            // begin async call to web request. 
            IAsyncResult asyncResult = webRequest.BeginGetResponse(null, null);

            // suspend this thread until call is complete. You might want to 
            // do something  
            asyncResult.AsyncWaitHandle.WaitOne();

            // get the response from the completed web request. 
            string soapResult;
            using (WebResponse webResponse = webRequest.EndGetResponse(asyncResult))
            {
                using (StreamReader rd = new StreamReader(webResponse.GetResponseStream()))
                {
                    soapResult = rd.ReadToEnd();
                }
                Console.Write(soapResult);
            }
        }

        private static HttpWebRequest CreateWebRequest(string url, string action)
        {
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
            webRequest.Headers.Add("SOAPAction", action);
            webRequest.ContentType = "text/xml;charset=\"utf-8\"";
            webRequest.Accept = "text/xml";
            webRequest.Method = "POST";
            return webRequest;
        }

        private static XmlDocument CreateSoapEnvelope()
        {
            XmlDocument soapEnvelop = new XmlDocument();
            try
            {
                string path =@"C:\myfiles\XMLFile.xml";
                if (File.Exists(path))
                {
                    soapEnvelop.Load(path);
                    string xmlcontents = soapEnvelop.InnerXml;
                    soapEnvelop.LoadXml(xmlcontents);
                }
              
            }
            catch (Exception ex) 
            {

                throw ex;
            }
          
            return soapEnvelop;
        }