perltk: error getting values from dynamically generated combo boxes

[ruhroh]

Hi perl monks, I am having an issue with retrieving values from a dynamically generated group of combo boxes. I am using an array to hold all of these combo boxes. I can only seem to access the most recent combo box and I get an error whenever I try to access the contents of an older combo box (so if I have two combo boxes, I get an error when I try to access the first one).

Here is the error that I get: Tk::Error: bad listbox index "": must be active, anchor, end, @x,y, or a number at /usr/intel/pkgs/perl/5.8.5/lib/site_perl/5.8.5/x86_64-linux/Tk.pm line 247. Tk callback for .browseentry.toplevel.frame.listbox Tk callback for .button1 Tk::__ANON__ at /usr/intel/pkgs/perl/5.8.5/lib/site_perl/5.8.5/x86_64-linux/Tk.pm line 247 Tk::Button::butUp at /usr/intel/pkgs/perl/5.8.5/lib/site_perl/5.8.5/x86_64-linux/Tk/Button.pm line 111 <ButtonRelease-1> (command bound to event)

Here is my code:

use strict;
use warnings;
use Tk;

my $fieldcounter = 0;
my $textboxrow = 1;
my $fieldbuttonrow = 2;
my @be;
my @listb;

my $mw = tkinit;

$mw -> geometry("400x200");
$be[$fieldcounter] = $mw->BrowseEntry(-label=>"Field") ;
$listb[$fieldcounter] = $be[$fieldcounter]->Subwidget('slistbox')->Sub
+widget('scrolled');
my @content;


tie @content,'Tk::Listbox', $listb[$fieldcounter];
@content = qw/dog
          cat
          mouse/;
my $button = $mw->Button(-text => 'Add Field',-command => \&addtextbox
+,);
my $button2 = $mw->Button(-text => 'Print texts',-command => \&printte
+xts,);

$be[$fieldcounter] -> grid(-row=>$textboxrow,-column=>2);
$button ->grid(-row=>$fieldbuttonrow,-column=>2,-columnspan=>2);
$button2 ->grid(-row=>$fieldbuttonrow+1,-column=>2,-columnspan=>2);
MainLoop();

sub addtextbox{
$fieldcounter++;
$fieldbuttonrow++;
$textboxrow++;

$be[$fieldcounter] = $mw->BrowseEntry(-label=>"Field");
$listb[$fieldcounter] = $be[$fieldcounter]->Subwidget('slistbox')->Sub
+widget('scrolled');

tie @content,'Tk::Listbox', $listb[$fieldcounter];
@content = qw/dog
          cat
          mouse/;
$be[$fieldcounter] -> grid(-row=>$textboxrow,-column=>2);
$button->grid(-row=>$fieldbuttonrow,-column=>2,-columnspan=>2);
$button2->grid(-row=>$fieldbuttonrow+1,-column=>2,-columnspan=>1);

}

sub printtexts{

my $field_id;
my $field;
my $fields;
my @fieldslist;


for my $listb_index(0 .. $fieldcounter){
print "listb_index is $listb_index\n";
  $field_id = $listb[$listb_index] -> curselection();
  $field = $listb[$listb_index] -> get($field_id);
  push @fieldslist, $field;
}

$fields = join (':', @fieldslist);
print "fields is: $fields\n";


}