[Mailman-Users] How to change subscriber address

[Mailman Users]

I'm running Mailman 2.1.9 with RHEL.
    Red Hat Enterprise Linux AS release 3 (Taroon Update 1)

The question is how can a user change their subscription address?

The web page http://system.name/mailman/options/listname
shows a place to enter a new address.  This does not actually
change the user's subscription address.

What do I have wrong here?

Thanks.

Charlie Smith
charlie at elektro.cmhnet.org