tage data fra xml node og sende i min post data webrequest

jeg har en xml fil som jeg automatisk opretter hver gange, jeg trykker send. Mit problem er at når jeg laver min webrequest. Og vil poste min xml fil tilbage til server, siger den der ingen data er.

// creating object of XML DOCument class 
        XmlDocument XmlDocObj = new XmlDocument();
        //loading XML File in memory 
        XmlDocObj.Load(Server.MapPath("opretTur.xml"));
        //Select root node which is already defined 
        XmlNode RootNode = XmlDocObj.SelectSingleNode("CreateTour");

        //Customers
        XmlNode createNode = RootNode.AppendChild(XmlDocObj.CreateNode(XmlNodeType.Element, "Customer", ""));

        createNode.AppendChild(XmlDocObj.CreateNode(XmlNodeType.Element, "RecordType", "")).InnerText = "CreateTour";
        createNode.AppendChild(XmlDocObj.CreateNode(XmlNodeType.Element, "UserId", "")).InnerText = Guid.NewGuid().ToString();
        createNode.AppendChild(XmlDocObj.CreateNode(XmlNodeType.Element, "CustomerNumber", "")).InnerText = "KundeNR";
       
gemmer min xml node
XmlDocObj.Save(Server.MapPath("opretTur.xml"));

prøver at sende den til server efter jeg har gemt
Min WebRequest
  // Create a request using a URL that can receive a post.
        WebRequest request = WebRequest.Create("min url");
        // Set the Method property of the request to POST.
        request.Method = "POST";
        // Create POST data and convert it to a byte array.


        //string postData = XmlDocObj["RecordType"].InnerText + XmlDocObj["UserId"].InnerText + XmlDocObj["CustomerNumber"].InnerText;

        string postData = ("opretTur.xml");
       
        byte[] byteArray = Encoding.UTF8.GetBytes(postData);
        // Set the ContentType property of the WebRequest.
        request.ContentType = "application/xml";
        // Set the ContentLength property of the WebRequest.
        request.ContentLength = byteArray.Length;
        // Get the request stream.
        Stream dataStream = request.GetRequestStream();
        // Write the data to the request stream.
        dataStream.Write(byteArray, 0, byteArray.Length);
        // Close the Stream object.
        dataStream.Close();
        // Get the response.
        WebResponse response = request.GetResponse();
        // Display the status.
        Console.WriteLine(((HttpWebResponse)response).StatusDescription);
        // Get the stream containing content returned by the server.
        dataStream = response.GetResponseStream();
        // Open the stream using a StreamReader for easy access.
        StreamReader reader = new StreamReader(dataStream);
        // Read the content.
        string responseFromServer = reader.ReadToEnd();
        // Display the content.
        Console.WriteLine(responseFromServer);
        // Clean up the streams.
        reader.Close();
        dataStream.Close();
        response.Close();