#!/usr/bin/perl
use warnings;
use diagnostics;
use Tk;
$top = MainWindow->new();
$wine_list = $top->Listbox("width" => 20, "height" => 5
)->pack();
$wine_list->insert('end', # Insert the following list at end 
"Napa Valley Chardonnay", "Cabernet Sauvignon",
"Dry Chenin Blanc", "Merlot", "Sangiovese" );
$wine_list->bind('<Double-1>', \&buy_wine);
sub buy_wine {
my $wine = $wine_list->get('active');
return if (!$wine);  # Return if no list item is active 
print "Ah, '$wine'. An excellent choice\n";
# Remove the wine from the inventory 
#$wine_list->delete('active'); 
}
MainLoop();