[Mailman-Users] cant create new lists ?

[Mehmet Fatih AKBULUT]

hi all,
i cannot create new lists.
getting the errors below :
*You are not authorized to create new mailing lists*
You can create a new mailing list by entering the relevant information into
the form below. The name of the mailing list will be used as the primary
address for posting messages to the list, so it should be lowercased. You
will not be able to change this once the list is created.
You also need to enter the email address of the initial list owner. Once the
list is created, the list owner will be given notification, along with the
initial list password. The list owner will then be able to modify the
password and add or remove additional list owners.
If you want Mailman to automatically generate the initial list admin
password, click on `Yes' in the autogenerate field below, and leave the
initial list password fields empty.You must have the proper authorization to
create new mailing lists. Each site should have a *list creator's* password,
which you can enter in the field at the bottom. Note that the site
administrator's password can also be used for authentication.

what is missing ? i did everything as supposed to be ? i am the mailowner
and administrator ?
what should i do to create new mailing lists ?

and the second question i want to ask is about images.
i installed mailman using apt-get install. but images not shown on pages.
where exactly i move images directory to be able to see icons on pages ?
my cgi-bin directory : /usr/lib/cgi-bin and mailman is under this directory.
other malman directories are : /etc/mailman /usr/lib/mailman and
/usr/share/mailman.
i have :
localhost:/usr/lib/mailman# ls
bin  cron  mail  Mailman  scripts
and put images folder in some places but didnt find the correct one ;)
help me please.
thanks in advance,
bye.