The SET-CALLBACK attribute on the PROCEDURE widget has inval

I'm trying to define a new SOAP-HEADER for my web service using this sample: http://documentation.progress.com/output/OpenEdge102b/oe102bhtml/wwhelp/wwhimpl/js/html/wwhelp.htm#href=dvwsv/16dvwsvC09soapHeader.18.5.html

I'm working with OOABL classes, so I've change the code from SET-CALLBACK-PROCEDURE to SET-CALLBACK.

Intead this modification, I become the error-message (4065)...

Have somebody an idea ?

Here's my code:

method public void Create( ):

define variable g_header as handle no-undo.
define variable gCallback as logical no-undo.


/* Set up a proxy for the service interface. This uses the Port Type name */
create server hWebService.
hWebService:connect("-WSDL 'svr-de-windrea2.ivnet.ch/.../Kinetic.Services.StreamService.svc
-Binding streamEndpointConfig
-SOAPEndpoint endpoint-URL'").

if not hWebService:connected() then do:
message "SERVER: " skip "svr-de-windrea2.ivnet.ch/.../Kinetic.Services.StreamService.svc skip
"is not connected"
view-as alert-box info buttons ok.
end.
/* use the Port type name here to create proxy and set a handle to it */
run StreamService set hStreamService on hWebService.

if not valid-handle(hStreamService) then do:
message "PortType: " valid-handle(hStreamService) " is not valid"
view-as alert-box info buttons ok.
end.

g_header = BuildRequestHeader("MyFile.txt", "4").

gCallback = hStreamService:set-callback ("REQUEST-HEADER", "ReqHandler").

delete object g_header.

end method.

method public static final void ReqHandler( output hHeader as handle, input cNamespace as character, input cLocalNS as character, output lDeleteOnDone as logical ):

lDeleteOnDone = false.

end method.