WCF / ASMX :: Passing SoapHeader To Java Web Service

I have web service (.NET 2.0), in this i have added proxy class of my client's web service. Client's web service is in Java. I have to pass SOAP requet in following format

<soap:Envelope xmlns:soap="[URL]xmlns:xsd="[URL]xmlns:xsi="[URL]instance">
<soap:Header>
<AuthenticationToken xmlns="[URL]
<Username xmlns="[URL]XXX</Username>
<Password xmlns="[URL]YYY</Password>
</AuthenticationToken>
</soap:Header>
<soap:Body>
</soap:Body></soap:Envelope>
for this i have written following code but it's giving error as "Request must include authentication token"
-- code start--
public class WebService : System.Web.Services.WebService {
public WebService () {
//Uncomment the following line if using designed components
//InitializeComponent();
}
public MyHeader AuthenticationToken = new MyHeader();
public MyHeader MyHeader
{
get { return AuthenticationToken; }
set { AuthenticationToken = value; }
}
[WebMethod]
[SoapHeader("AuthenticationToken")]
public string HelloWorldTest1()
{
AuthenticationToken .Password = "username";
AuthenticationToken .Username = "password";
ClientWebServices s1 = new ClientWebServices();
string soapbody="";
string res=s1.addmethod(soapbody);
return res;
}// end of method
} //end of service class
public class MyHeader : SoapHeader
{
public string Username;
public string Password;
}
-- code end--