I found the solution myself. I have to use NetworkCredential for this webservice
locred = lobridge.createinstance("System.Net.NetworkCredential","WS4SNTRC","ed5R#CK5") loService.OSERVICE.Credentials = locred loService.OSERVICE.Url="http://qas.sanitrace.be/int/QAS_Sanitel_ExtInterfacingSvcs/SanitelServices.asmx"
Regards, Paul