my $process;
$process = Gtk2::Helper->add_watch( fileno( $input ), in => sub {
    if ( eof( $input ) ) {
my $finished = Gtk2::Dialog->new ('La conversion est finie', undef,'destroy-with-parent',				                                                'ok' => '4');
$label = Gtk2::Label->new("le mp3 se trouve a l'endroit suivant: $save_as");
$finished->vbox->add ($label);
$finished->signal_connect (response => \&quit );
$finished->show_all;
last;
}
     else {
Gtk2->main_iteration while Gtk2->events_pending;
$progressbar->pulse;
usleep(100000);
}
    return 1;
} );