The web service you are trying to consume offers a WSDL at the following address. So simply right click on the References in the solution explorer and use the Add Service Reference dialog in Visual Studio and point to the WSDL and it will generate strongly typed classes for you to easily consume the service, just like this:
protected void sendSoapMessage()
{
using (var client = new RegistrationBindingsClient("RegistrationBindings"))
{
var registration = new RegistrationType();
registration.Source = new SourceType();
registration.Source.SourceID = "50001255";
registration.Email = "adsvine@gmail.com";
registration.FirstName = "Muz";
registration.LastName = "Khan";
var countryUK = new CountryTypeUK();
countryUK.CountryID = 2000077;
countryUK.Language = 2000240;
countryUK.Address = new AddressTypeUK();
countryUK.Address.Postalcode = "N19 3NU";
registration.Item = countryUK;
registration.DOB = new DateTime(1977, 3, 8);
registration.Gender = 2000247;
client.SubmitPanelist(registration);
}
}
See how easy it is. You should not worry about any SOAP and XML plumbing.
And if you are interested in the actual underlying SOAP envelope that is being sent on the wire using this request: