error when adding a custom element to a SOAP Header in c#

[OurManInBananas]

I am new to SOAP and web-services, and not an expert on c# either so sorry if I have made an infuriatingly simple error.

I am calling several web-services and I now need to add an element called *pcimask* to the SoapHeader in order to get a response that is PCI Compliant.

The web-services/WSDL don't expose this property so I guess I need to add it at runtime.

My application creates SOAP messages like the below: (the Soap Request and Response are output into a text file by a SOAP Logging class)

 <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:Header>
	    <AutHeader xmlns="http://edb.com/ws/WSCommon_v21">
		<SourceApplication>myApp</SourceApplication>
		<DestinationApplication>theirApp</DestinationApplication>
		<Function>CardCreate</Function>
		<Version>3.0.0</Version>
		<ClientContext>
			<userid>myID</userid>
			<credentials>SecureToken</credentials>
			<channel>NBA</channel>
			<orgid>123456</orgid>
			<orgunit>654321</orgunit>
			<customerid />
			<locale xsi:nil="true" />
			<ip>123.456.789.012</ip>
		</ClientContext>
	</AutHeader>
    </soap:Header>

As I understand it, I need to add an element `pcimask="true` to the `<ClientContext ` element, and it must be after the `<ip>`

However the wsdl doesn't expose this as a property.

So I have looked at the below resources:

• http://bytes.com/topic/net/answers/5...r-soap-message
• http://stackoverflow.com/questions/1...b-service-call
• http://stackoverflow.com/questions/4...r-in-spring-ws

and I came up with a little class inside my common.cs as below:

 using System.Web.Services.Protocols;
    using System.Xml.Serialization;

    namespace EvryCardManagement
    {
        [XmlRoot(Namespace = "http://edb.com/ws/WSCommon_v21")]
        [SoapHeader("EDBHeaderType", Direction = SoapHeaderDirection.In)]

        public class CardCreateEx : SoapHeader
        {
            public string Value;
            public CardCreateEx pcimask;

        }

        public static class Common
            {
            public static bool closeMe { get; set; }

            public static int iMQRowID;

            public static string impNme;
            public static string impPwd;

and I wanted to try and use it in my code that creates the SoapHeader as below:

 private EDBHeaderType wsSoapHeader()
        {
            EDBHeaderType wsSoapHeader = new EDBHeaderType();

            /* ClientContext */
            ClientContextType clientContext = new ClientContextType();

            clientContext.userid = edb_service[0].userid;

            clientContext.credentials = Common.SOToken;
            
            //clientContext.pc
            clientContext.orgid = edb_service[0].orgid;
            clientContext.orgunit = edb_service[0].orgunit;
            clientContext.customerid = "";
            clientContext.channel = edb_service[0].channel;
            clientContext.ip = edb_service[0].ip;

            /* PCI MASK added to ClientContext in header; P-02925; Jan 2015 */
            CardCreateEx cardCreateExt = new CardCreateEx(); //  P-02925; Jan 2015
            cardCreateExt.Value = "true";
                                    
            /* EDBHeader */
            wsSoapHeader.SourceApplication = edb_service[0].SourceApplication;
            wsSoapHeader.DestinationApplication = edb_service[0].DestinationApplication;
            wsSoapHeader.Function = edb_service[0].Function;
            wsSoapHeader.Version = edb_service[0].Version; //  P-02925; Oct-Nov 2014
            wsSoapHeader.ClientContext = clientContext;

            return wsSoapHeader;
        }

but I get a build error:

Attribute 'SoapHeader' is not valid on this declaration type. It is only valid on 'method' declarations.

so what is the correct way to do this?