Following function will expect a generic List and serialize into xml and make an http post request and after receiving response it will again deserialize xml into generic list:-

    public customer CreateOrder(customer objCustomerRequest)
    {
      customer objCustomer = new customer();
        if (objCustomerRequest == null)
        {
            throw new ArgumentNullException("composite");
        }
        else
        {
            List<customer> customerList = new List<customer>();
            XmlSerializer xmlSerializer = new XmlSerializer(objCustomer.GetType());
            StringWriter textWriter = new StringWriter();

            xmlSerializer.Serialize(textWriter, objCustomer);

            string objresult = getXMLString(textWriter.ToString(), "customers");
            StringReader XmlDeserializer = new StringReader(objresult);

            return (customer)xmlSerializer.Deserialize(XmlDeserializer);
            ///return js.Deserialize(objresult);
        }
    }



public string getXMLString(string xmlContent, string url)
        {
            string Url;
            string sResult;
            Url = System.Configuration.ConfigurationManager.AppSettings["UserURl"] + url;
            var httpWebRequest = (HttpWebRequest)WebRequest.Create(Url);
            httpWebRequest.ContentType = "text/xml";
            httpWebRequest.Method = "POST";
            using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
            {
                streamWriter.Write(xmlContent);
                streamWriter.Flush();
                streamWriter.Close();
                var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
                {
                    var result = streamReader.ReadToEnd();
                    sResult = result;
                }
            }
            return sResult;
        }