disallow creating of directories

[tony]

Hi all!

Does anybody know how I can create a share where users are not
allowed to create a directory but only to create files in the given
directory structure. They must have write access to existing directories.

My current configuration is kind of a workaround; With these options
users can create directories but cannot access or delete them
afterwards. So after a while there are some "new directory" dirs,
which can only be removed by admins; i've put up a cron-script which does
this periodically, but anyhow - no nice solution:

[transfer]
    comment             = Transferlaufwerk
    path                = /raid/samba/transfer
    create mode         = 660
    directory mode      = 000
    inherit permissions = no
    valid users         = @sambausers @ntadmin
    force group         = sambausers
    force user          = transfer
    writeable           = yes


Any idea how to do it better?
Thanx in advance
tony