Here's a more complete example:

#!perl -w
use strict; # always

use Tk;

my $Window = MainWindow->new(-title => "Test Window");
my $uframe =$Window->Frame()
    ->pack(-side   => 'top',
       -fill   => 'both',
       -expand => 1);
my $dframe =$Window->Frame()
    ->pack(-side   =>'top',
       -fill   => 'x');

my $txtWidget = $uframe->Scrolled("Text")
    ->pack(-side   => 'top',
       -fill   => 'both',
       -expand => 1);

my $pasteBtn = $dframe->Button(-text     => "Paste",
                   -command  => sub { $txtWidget->insert('end',"blah b
+lah") })
    ->pack(-side => 'left');
my $clearBtn = $dframe->Button(-text    => "Clear",
                   -command => sub { $txtWidget->delete('0.0','end') }
+)
    ->pack(-side => 'left');

MainLoop();
[download]

Cheers,
Shendal