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

my $mw=tkinit;

my $text = $mw->Scrolled('Text')->pack;

$text->bind('<Return>',[sub { &check_limit   }]);

$mw->Button(-text=>'Press Me', -command=>sub {
     $text->insert('end',$i++."\n");
     $text->see('end');
     &check_limit;
  })->pack;

$mw->Button(-text=>'Exit', 
     -command=>sub {exit})->pack;

for (1..198){
$text->insert('end',$_."\n");
     $text->see('end');
}

MainLoop;

sub check_limit{
  $text->delete('1.0', "end -200 lines");
}