# minimum code to illustrate point
# based on example in 'CGI programming with Perl'

use CGI;
use CGI::Carp qw( fatalsToBrowser set_message );
$CGI::HEADERS_ONCE = 1;

BEGIN {
  sub carp_error {
    my $message = shift;
      error( $message )
  }
  CGI::Carp::set_message( \&carp_error )
}

my $q = new CGI;

# time passes

# the next line wouldn't cause a duplicate header
# die;

print	$q->header( 'text/html' );

# this next line would
# die;

# send the broswer a message

print "test";
exit;

sub error{
  # die nicely
  exit
}

##</code><code>##

print	$q->header( 'text/html' );