HTTP listener not running

I've just installed Oracle 9iDS, and I'm playing with Oracle Forms. When I try to run a form , I get this message: The HTTP Listener is not running on comp_name at port 8888.
I also have Oracle 9.2 installed and the Oracle Listener is started.
Could anyone help me how to start HTTP listener?

Thank you

You have to start the OC4J instance which simulate the Forms Servlet to run any Forms developed in 9iDS, 10gDS