The flash does not have a usermanagment - he has a login functionality with the users you manage.
TFU is intended to use e.g. in TWG where I do already have a user management and there I create, manage users, directories ....
Normally you should implement a small app where users can create their accounts (if you really want this). This is not a task that should be done in the flash because this are simple entry masks that are much more flexible if you do this e.g. in php.
test/test is hardcoded in the backend as example (in TWG I use of course my user management).
When I'm bored (and this normally does NOT happen) I maybe add a little user management to the flash (a .htuser where you can enter users, password and the upload directory).
But actually someone who uses it can do this
.
/Michael