Help Needed in Adding AuthenticationHeader in SOAP request

Hi,

I would like to call SOAP service without proxy class and below the source code i found on the internet.

 public static class SOAPHelper
    {
        /// <summary>
        /// Sends a custom sync SOAP request to given URL and receive a request
        /// </summary>
        /// <param name="url">The WebService endpoint URL</param>
        /// <param name="action">The WebService action name</param>
        /// <param name="parameters">A dictionary containing the parameters in a key-value fashion</param>
        /// <param name="soapAction">The SOAPAction value, as specified in the Web Service's WSDL (or NULL to use the url parameter)</param>
        /// <param name="useSOAP12">Set this to TRUE to use the SOAP v1.2 protocol, FALSE to use the SOAP v1.1 (default)</param>
        /// <returns>A string containing the raw Web Service response</returns>
        public static string SendSOAPRequest(string url, string action, Dictionary<string, string> parameters, string soapAction = null, bool useSOAP12 = false)
        {
            // Create the SOAP envelope
            XmlDocument soapEnvelopeXml = new XmlDocument();
            var xmlStr = (useSOAP12)
                ? @"<?xml version=""1.0"" encoding=""utf-8""?><soap12:Envelope xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance""
                      xmlns:xsd=""http://www.w3.org/2001/XMLSchema""
                      xmlns:soap12=""http://www.w3.org/2003/05/soap-envelope""><soap12:Body><{0} xmlns=""{1}"">{2}</{0}></soap12:Body></soap12:Envelope>"
                : @"<?xml version=""1.0"" encoding=""utf-8""?><soap:Envelope xmlns:soap=""http://schemas.xmlsoap.org/soap/envelope/""
                        xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance""
                        xmlns:xsd=""http://www.w3.org/2001/XMLSchema""><soap:Body><{0} xmlns=""{1}"">{2}</{0}></soap:Body></soap:Envelope>";
            string parms = string.Join(string.Empty, parameters.Select(kv => String.Format("<{0}>{1}</{0}>", kv.Key, kv.Value)).ToArray());            

            var s = String.Format(xmlStr, action, new Uri(url).GetLeftPart(UriPartial.Authority) + "/", parms);
            soapEnvelopeXml.LoadXml(s);

            // Create the web request
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
            webRequest.Headers.Add("SOAPAction", soapAction ?? url);
            webRequest.ContentType = (useSOAP12) ? "application/soap+xml;charset=\"utf-8\"" : "text/xml;charset=\"utf-8\"";
            webRequest.Accept = (useSOAP12) ? "application/soap+xml" : "text/xml";
            webRequest.Method = "POST";

            // Insert SOAP envelope
            using (Stream stream = webRequest.GetRequestStream())
            {
                soapEnvelopeXml.Save(stream);
            }

            // Send request and retrieve result
            string result;
            using (WebResponse response = webRequest.GetResponse())
            {
                using (StreamReader rd = new StreamReader(response.GetResponseStream()))
                {
                    result = rd.ReadToEnd();
                }
            }
            return result;

        }
    }

my try : 

Dictionary<string, string> parameters = new Dictionary<string, string>();
                Dictionary<string, string> Headers = new Dictionary<string, string>(); 
                Headers.Add("CustomerID", "Test1");
                Headers.Add("UserID", "NTest1");
                Headers.Add("Password", "Sample");
                parameters.Add("id", "1");
                string Headerparms = string.Join(string.Empty, Headers.Select(kv => String.Format("<{0}>{1}</{0}>", kv.Key, kv.Value)).ToArray());
                string URL = "https://Myxxx.com/webservices/8.0/searchapi1.asmx?op=GetResultDetails";
                var SoapResponse = SOAPHelper.SendSOAPRequest(URL, "GetResultDetails", parameters, Headerparms);        

since my client webservice name is sensitive, i masked that. sorry about that. i am not sure how to add the authentication header in the above code(SOAPHelper) to make it work,  below the actual xml i tried in post man which worked. but i am not sure how  to make it wok Programmatically with the above c# code. Please help me 

<?xml version="1.0" encoding="UTF-8"?><s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"><s:Header><h:AuthenticationHeader xmlns:h="https://myxxx.com/webservices/8.0" xmlns="https://myxxx.com/webservices/8.0" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><CustomerID>Test1</CustomerID><UserID>NTest1</UserID><Password>Sample</Password></h:AuthenticationHeader></s:Header><s:Body xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><GetResultDetails xmlns="https://myxxx.com/webservices/8.0"><id>1</id></GetResultDetails></s:Body></s:Envelope>