$login_menubutton->bind(<Mouse-1>, \&login_procedure); 
my $password_box;
my $password_box_frame;
my $password_box_entry;
my $password_box_exit;
sub login_procedure {
      if ( not ( Tk::Exists( $password_box ) ) ) {
              $password_box = $login->Toplevel();
              $password_box_frame = $password_box->Frame()->pack();
              $password_box_entry = $password_box_frame->Entry(-show);
              $password_box_exit = $password_box_frame->Button(-text, 'Ok', -command, \&something_with_password)->pack(-side, 'bottom');
}