use strict;
use warnings;
use XML::Twig;

# Select Twig bassed on value of id attribute on Person element
my $twig= new XML::Twig( 
                twig_handlers =>                  
                  { 'Person[@id="50000"]' => \&Person } 
                       );  
$twig->set_pretty_print ('record'); # Human readable output please
$twig->parsefile( "dharry.xml");             
$twig->flush;

sub Person { 

	my( $twig, $person)= @_;
	
	my $name = $person->first_child("First");
	$name->set_text("dHarry");
	$twig->flush;

}