in the TDSHTTPService component in a Datasnap Service Application, how can I change the HTTP Port at run time before it starts listening. I tried changing HTTPPort on ServiceStart (and ServiceCreate), but it won't listen on the new port, it always listens on the port it had at design time.

in the TDSHTTPService component in a Datasnap Service Application, how can I change the HTTP Port at run time before it starts listening.  I tried changing HTTPPort on ServiceStart (and ServiceCreate), but it won't listen on the new port, it always listens on the port it had at design time.   

Does anyone know how to make the port configurable?