G'day PilotinControl,

Issues with the code you posted:

• Get into the habit of using lexical filehandes and the 3-argument form of open. The documentation has details.
• Check that your I/O was actually successful. Either hand-craft code for every I/O operation (open has examples) or use the autodie pragma; the latter is my normal preference as it's both less error-prone and far less work.
• You read all your data twice (while and for loops). You only need to do this once.
• I found your use of $lines (plural) confusing on first reading. That variable contains a single line: $line would be more appropriate and less of a maintenance issue.
• You chomp the array on every iteration of the for loop. You should do this once before you start the loop.
• You create a Tk::BrowseEntry widget on every iteration of the for loop. You should do this once before you start the loop.
• See insert() in the Tk::BrowseEntry METHODS section. The syntax is insert(index, string). Your usage of insert(index, array) possibly explains the earlier my @owners = $owner[1]; (which I found confusing when I first encountered it).
• While you can chain methods (e.g. BrowseEntry->pack->insert), you don't have to. Assign widgets you create to a variable; subsequently, use that variable to invoke methods.

The following script shows the guts of what you need.

#!/usr/bin/env perl

use strict;
use warnings;

use Tk;
use Tk::BrowseEntry;

my $mw = MainWindow->new;

my $ctrl_F = $mw->Frame->pack(-side => 'bottom');
$ctrl_F->Button(-text => 'Exit', -command => sub { exit })->pack;

my $app_F = $mw->Frame->pack(-side => 'top');
my $be = $app_F->BrowseEntry->pack;

while (<DATA>) {
    chomp;
    $be->insert(end => (split /:/)[1]);
}

MainLoop;

__DATA__
prefix:Owner A
prefix:Owner B
prefix:Owner C
[download]

As you can see, although that's very short, it's a working script that you can run (as is). It contains no distracting noise (e.g. widget decorations, foreground/background colours, etc.) and merely addresses the issue at hand. Please attempt to provide something like this when you post your next question.