Friday is "free pizza day" at my place. Of course this script will only get you "part way there", about as worthy as a $5.00 pizza. :-) You will need to add scrolling(hint: add a frame first, then add a Scrolled Text to the frame), and you will need to devise bindings to return the line number selected. But I will leave that to you, what do you expect for $5.00?, you won't get a full load of toppings.

#!/usr/bin/perl
use Tk;
use Tk::DialogBox;

my $file = shift || $0;

my $mw = MainWindow->new;

my $dialog = $mw->DialogBox(
    -buttons => [qw/Ok Cancel/],
    -title   => "Enter New Value"
);

my $dialogT = $dialog->add("Text");
$dialogT->pack(qw/-padx 10 -pady 10/);

my $button = $mw->Button(
    -text    => "Get new value...",
    -command => [ \&getNewValue, $file ]
)->pack(qw/-side left -padx 10/);

MainLoop;

sub getNewValue {

    my $filein = shift;
    open(FH,"<$filein") or warn "$!\n";
    my $text = do {local $/; <FH>};

    $dialogT->insert('end',$text);


## Determine whether or not the user hit "Ok" 
    my $button = $dialog->Show();
    if ( $button eq "Ok" ) {
        my $letters = $dialogT->get( '1.0', 'end' );
        print "$letters was submitted\n";

    }
}
__END__
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