>I need to use a SOAP Header to access a web service.

This is from the .NET help "Securing XML Web Services Created Using ASP.NET"

    // Create a new instance of an XML Web service proxy class.
    SecureWebService s = new SecureWebService();

    // Create the Authentication SOAP header and set values.
    Authentication a = new Authentication();
    a.User = user.Value;
    a.Password = password.Value;

    // Assign the Header.
    s.AuthenticationValue = a;

      string result = s.ValidUser();
      span1.InnerHtml = result;

I think you will have to inspect your proxy class code to replace that Authentication() call with the one that the web service defines. There is a SoapHeader framework class that you have to work with.

By the way, how are you creating your proxy code? Are you using the wsdl.exe? Do you know if there is any GUI interface instead of using the command line?

-Dave