my $ok_but = $bf->Button(
                  -text => 'Continue', 
                  -width => 10,
                  -command => sub {
                   ($idx) = $list_box->curselection(); 
                   if ( defined $idx ){
                       $job = $jobs[$idx];
                       $mw->destroy();
                   } else { 
                       $mw->destroy();
                   }  
                   )->pack(-side => 'bottom',
                           -padx => 10,
                           -pady => 5);

##</code><code>##

$top->Mainloop();
return $job if defined $job;
return 0;