GUI Perl

#!/usr/bin/perl -w
use Tk;
$side = "bottom";
$Tk::strictMotif = 1;
$main = MainWindow->new();
$button1 = $main->Button(-text => "Button 1",
                         -command => \&exit_button);
$button1->pack(-side=>$side);
$button2 = $main->Button(-text => "Button 2",
                         -command => \&exit_button);
$button2->pack(-side=>$side);
$button3 = $main->Button(-text => "Button 3",
                         -command => \&exit_button);
$button3->pack(-side=>$side);
MainLoop();
sub exit_button {
    print "You pushed the button!\n";
    exit;
}