use warnings;
use Tk;
use strict;

# Das mw erzeugen
my $mw = MainWindow->new();

$mw->Label(-text => '    One-Click-Event    ')->pack();

my $message;

my $list = $mw->ScrlListbox(-label           => 'Single Selection', 
                            -selectmode      => 'single', 
                            -height          => 5, 
                            -exportselection => 0)->pack(); 

my $lbl = $mw->Label(-textvariable => \$message)->pack();

for(0..10)
  { $list->insert('end', 'Auswahl ' . $_); } 

$list->bind('<Button-1>', sub { $message = $list->Getselected(); }); 

MainLoop;