GUI Perl

#!/usr/bin/perl -w
use Tk;
$quality = "letter";
$main = MainWindow->new();
$label = $main->Label(-text => "Print Options");
$label->pack();
$frame = $main->Frame(-relief=>"groove",
                      -borderwidth=>2);
$radio1 = $frame->Radiobutton(-text=>"Draft",
                              -variable=>\$quality,
                              -value=>"draft");
$radio1->pack(-side=>"top");
$radio2 = $frame->Radiobutton(-text=>"Letter",
                              -variable=>\$quality,
                              -value=>"letter");
$radio2->pack(-side=>"top");
$frame->pack();
$button = $main->Button(-text => "Exit",
                        -command => \&exit_button);
$button->pack();
MainLoop();
sub exit_button {
    if ( $both_sides eq "both") {
        print "Print both sides.\n";
    } else {
        print "Print single-sided.\n";
    }
    
    exit;
}