sub setup {
    my $self = shift;
    $self->start_mode('main');
    $self->mode_param('cmd');
    $self->run_modes(
                     'main'    => 'main',
                     'search   => 'search', 
                     'addfoo'  => 'addfoo',
                     'editfoo' => 'editfoo',
                     'deletefoo' => 'deletefoo'
                     );

sub cgiapp_prerun {
   # determine run-mode
   # set/get session
   # is user logged in?
   return ok || goto login mode if run mode requires login and user is not logged in.
}

sub login {
   # display login page if no params
   # not sure how to get back here, but verify user and password
   # if not valid go to login with error message else..
   # set/get session and update logged in to 1.
}