sub setup { 
    my $self = shift; 
    $self->start_mode('mode1'); 
    $self->run_modes( 
       'mode1' => 'helloworld_cgi_app1', 
       'mode2' => 'helloworld_cgi_app2', 
       'mode3' => 'helloworld_cgi_app3', 
       ); 
}