nsIWebServiceProxyFactory in Firefox 1.5

 Create a service proxy. Loading of the WSDL URL will occur
 in a synchronous manner. Calls to web service can be made as
 soon as this method completes.

 @param wsdlURL The URL of the WSDL service description. This
                description will be loaded and used as the basis
                for the service proxy.
 @param portname The name of the port of the service that this 
                 service proxy represents. Currently the port
                 must represent a SOAP binding.
 @param qualifier The user-specified qualifier is incorporated into
                  the names of XPCOM interfaces created for the 
                  service proxy. For C++ callers, this qualifier 
                  should be the  same one used in creating the IDL 
                  used at compile time. Script callers need not 
                  specify a qualifier.
 @param isAsync If PR_TRUE, the method signatures of the service
                proxy represent an asynchronous calling convention.
                A callback instance must be registered with the proxy.
                A method call to a web service is only completed when
                the corresponding callback method is invoked.
                If PR_FALSE, the method signatures of the service
                proxy represent a synchronous callling convention.
                A method call to a web service is completed when the
                method call to the proxy returns.

 Create a service proxy. Loading of the WSDL URL will occur
 in an asynchronous manner. Methods on the listener instance will
 be invoked when the proxy has been created. Any method invocations
 on the service proxy prior to asynchronous completion of the 
 intialization step will fail. The caller is guaranteed that this
 method will return before the listener is invoked.

 @param wsdlURL The URL of the WSDL service description. This
                description will be loaded and used as the basis
                for the service proxy.
 @param portname The name of the port of the service that this 
                 service proxy represents. Currently the port
                 must represent a SOAP binding.
 @param qualifier The user-specified qualifier is incorporated into
                  the names of XPCOM interfaces created for the 
                  service proxy. For C++ callers, this qualifier 
                  should be the same one used in creating the IDL 
                  used at compile time. Script callers need not 
                  specify a qualifier.
 @param isAsync If PR_TRUE, the method signatures of the service
                proxy represent an asynchronous calling convention.
                A callback instance must be registered with the proxy.
                A method call to a web service is only completed when
                the corresponding callback method is invoked.
                If PR_FALSE, the method signatures of the service
                proxy represent a synchronous callling convention.
                A method call to a web service is completed when the
                method call to the proxy returns.
 @param listener The callback instance which will be invoked when
                 the proxy is completely initialized.