When you use the New Service Wizard to define a new service, you have the choice of Finish or Add an operation. When you click Finish, you define an empty service file. Add an operation allows you to define a complete messaging or database service. In both cases, two files for the service (one with a wsdl extension and one with an iface extension) appear in Navigator. Before the empty service is usable, you must open the WSDL file and add the following pieces: