You should use
strict!
This code prints the selected entry when you double click on the entry:
#!/usr/bin/perl
use strict;
use warnings;
use Tk;
# Variables
my $bx_w = 80;
my %hash = (
"Test1" => [qw/a b c d/],
"Test2" => [qw/e f g h/],
);
my $mw = MainWindow->new();
$mw->title("test");
$mw->minsize(qw/79 4/);
#$mw->maxsize(qw/79 4/);
my $lz_f = $mw->Frame()->pack(-side =>'top',);
#&creation;
foreach my $label(keys %hash) {
my $lngth = $#{$hash{$label}};
my $lbl = $lz_f->Label(
-text => $label,
-bg => 'white',
-width => $bx_w,
)->pack(
-side => 'top',
-expand => 'both',
);
my $lstbx = $lz_f->Listbox(
-bg=>'lightgrey',
-relief=>'flat',
-height=>$lngth,
-width=>$bx_w,
)->pack(
-side=>'top',
);
foreach my $i ( 0 .. $#{ $hash{$label}} ) {
$lstbx->insert($i, $hash{$label}[$i]);
}
$lstbx->bind( '<Double-1>' => sub{ my ($index) = $lstbx->curselect
+ion; print $lstbx->get($index) } );
}
MainLoop();