super-TOPWINDOW ?

hi,

I want my App to have several windows floating around ? Do I have to create 
them with 'toplevel'  i.e. 

my $w1 = new Gtk::Window('toplevel');
my $w2 = new Gtk::Window('toplevel');
my $w3 = new Gtk::Window('toplevel');
.... code ...
..w1,w2,w3..show_all...

Or I have to create first one common Parent and subsequently $app->add() all of 
the Gtk::Windows to them ... and if yes which is this common-top-object ?

Thanx alot in advance 

raptor@xxxxxxxx