$dialog = $window->Dialog(    -title => "Dateneingabe",-default_button => 'Speichern',    -buttons    => 'Speichern', 'Abbrechen'],);
$dialog->add('LabEntry', -label="Eingabe", -textvariable = \$data);

if ($dialog->Show() eq 'Speichern')
{
   &do_something_on($data);
}