I have just delved into using Tk to design a simple flash card study program to help me review for mid-term exams. It uses a hash tied to a dbm file. I want to display the back of the card (i.e. the answer) in a popup message dialog when the "Flip" button is pressed. As so far I can get the message box to appear, but not the answer that should go inside of it (stored in $value).

#!/usr/bin/perl

$VERSION = 1.00;

use strict;
use Tk;
use Tk::FileSelect;
use Tk::MsgBox;

my ($value, %deck);

#main window
my $mw = MainWindow->new();
$mw->geometry("400x200");

#file selector
my $file_dialog = $mw->Button( 
         -text    => 'Load Cards',
         -command    => \&load_deck 
       ) ->grid(-row=>6,-column=>0);

#flip button
my $flip = $mw->Button(
         -text    => 'Flip',
         -command    => \&flip_card
       ) ->grid(-row=>6,-column=>2);

#next button
my $next = $mw->Button(
         -text    => 'Next =>',
         -command    => \&next_card
       ) ->grid(-row=>6,-column=>4);

#front label & display
$mw->Label( -text     => 'Front: ' )->grid(-row=>0);
my $front = $mw->Label()->grid(-row=>0,-column=>2);

#back display
my $back = $mw->MsgBox(-title=>'Back of card',-default=>'ok',-message=
+>$value);

$mw->Button( -text    => 'Quit', -command    => sub { exit } )
    ->grid(-row=>7,-column=>2);
MainLoop;

sub load_deck {
    my $start_dir = "/home/$ENV{'USER'}/TkPerl";
    my $FSref = $mw->FileSelect(-directory => $start_dir);
    my $file = $FSref->Show;
    dbmopen(%deck, $file, 0644);
    next_card();
}

sub next_card {
    my ($key, $loc_val) = each (%deck);
    $value = $loc_val;
    $front->configure(-text=>$key);
}

sub flip_card {
    my $pop = $back->Show;
}
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use strict;
use CGI;
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