use strict;
use warnings;
use Tk;
require Tk::BrowseEntry;
my @items = qw(check0 check1 check2);

my $mw = MainWindow->new();
my $default_choice = "check0";
my $dropDown = $mw->BrowseEntry(
   -label=>'item list',
   -variable=>\$default_choice,    
   -browsecmd=>\&run
   )->pack();

$dropDown->insert('end', "check0");
$dropDown->insert('end',"check1");
$dropDown->insert('end',"check2");
   
$mw->Button(-text=>'exit', -command=>sub{exit;})->pack();
MainLoop;


sub run{
    my $x = 0;
    foreach my $element (@items){        
        print $element eq lc($default_choice)? "$default_choice index [$x]\n" : next;
     $x++;
        }
    }