## This would be my main script, and I'll keep it 
## fairly simple. Notice that I'm using a module 
## called ContinueBox. ContinueBox is trivial, but let's 
## say that ContinueBox maps to the your child script. It 
## contains the functionality that you want to be easily
## reused.

use strict;
use Tk;
use ContinueBox;

my $mw = MainWindow->new;
my $dialog = $mw->ContinueBox;

$mw->Button(
   -text => "start child",
   -command => sub {
      my $result = $dialog->Show;

      ## I'm not doing much with the result here
      ## but I could use it terminate the entire
      ## script if I wante if the result was "Exit".
      print "$result\n";
})->pack;

MainLoop;

##</code><code>##

package ContinueBox;
use Tk;

use base qw(Tk::Toplevel);
Tk::Widget->Construct('ContinueBox');

sub Populate
{
   my ($cw, $args) = @_;
   $cw->SUPER::Populate($args);
   $cw->{Result} = "";
   
   ## SETUP CONTROLS
   $cw->Label(
      -text => "Would you like to continue?"
   )->pack(-side => 'top');

   my $bFrame = $cw->Frame->pack(-side => 'bottom');

   $bFrame->Button(
      -text => "Continue",
      -command => sub { $cw->{Result} = "Continue"; }
   )->pack(-side => 'left');
   
   $bFrame->Button(
      -text => "Exit",
      -command => sub { $cw->{Result} = "Exit"; }
   )->pack(-side => 'left');

   $cw->protocol(WM_DELETE_WINDOW => sub { 
      $cw->{Result} = "Exit"; 
   });
   $cw->withdraw;
}

sub Show {
   my $cw = shift;
   $cw->{Result} = "";
   $cw->deiconify;
   $cw->waitVariable(\$cw->{Result});
   $cw->withdraw;
   return $cw->{Result};
}
1;

##</code><code>##

package ContinueBox;
use Tk;

use base qw(Tk::DialogBox);
Tk::Widget->Construct('ContinueBox');

sub Populate
{
   my ($cw, $args) = @_;
   $args->{-buttons} = [qw/Continue Exit/],
   $args->{-default_button} = "Continue";
   $cw->SUPER::Populate($args);

   $cw->add("Label", -text => "Do you want to continue?")->pack;

   $cw->protocol(WM_DELETE_WINDOW => sub {
       $cw->Subwidget('B_Exit')->invoke;
   }); 
}
1;