Failed to install web access in Linux

After the successful installation of Database Server, Web Access Server, Broker and Interoperation Server, the process braked while the following command:
$DOORSHOME/bin/doors9 -interop -data 36655@hrcm -brokerHost hrcm -brokerPort 61616
The output of it is :
Information in /opt/ibm/Doors/InteroperationServer/mw/linux/system/international.reg has been successfully entered into the registry.
Cannot open X display "(not specified)".

my question is why it will depend on X display, and how to disable it.
SystemAdmin - Wed Feb 24 05:08:00 EST 2010

Re: Failed to install web access in Linux
Arllen - Wed Feb 24 10:41:07 EST 2010

Hi,

DWA on Linux requires an X display due to a requirement from a third-party tool it depends on. It cannot be disabled. You will need to set up a valid X display, which should be accessible to the user that starts the Interoperation Server.

Hope this helps,

Arllen