How can I know the display number from the issuing vncviewer side?

[Tom Wurgler]

I have a remote Linix computer setup with free realvnc 4.1.2 server to be
started via -inetd.  I start the free vncviewer 4.1.2 on my client system and
VNC comes up on the remote and all works great.  I want to write a script to
drive all this and start some applications etc and what I need to know (while in
the script) is the display number that will be used.  How can get at the display
number inside the script?

Thanks!