// for MSW (DDE classes), a_service is 'service name', apparently an arbitrary string
// for Unix, should be a valid file name (for a nonexistent file)
// for nonMSW, nonUnix, must be port number, for example "4242" (TCP/IP based classes)
// should be unique to the client app
// for MSW (DDE classes), a_service is 'service name', apparently an arbitrary string
// for Unix, should be a valid file name (for a nonexistent file)
// for nonMSW, nonUnix, must be port number, for example "4242" (TCP/IP based classes)
// should be unique to the client app