You can now select the Web method you wish to call. Web services typically offer the ability call there methods using a number of protocols.
The browser shows all the supported protocols and all the methods exposed for each of them.
For WSDL, the Web Service Test Client supports protocols, SOAP 1.1, SOAP 1.2, HTTP GET & HTTP POST. Any other protocols are ignored.
Once you select your method, and press Finish, and request is constructed for you.
You can then modify the request and call the web method. See Web Service Test Client.