use strict;
use XML::Twig;

my $file = 'uncle.xml';

my $twig = new XML::Twig;

$twig->parsefile($file);

my $root = $twig->root;
my @messages  = $root->children;

foreach my $msg (@messages) {
 my $error  = $msg->first_child('error');
 my $result = $msg->first_child('request');
 my $error_name  = $error->att('name');
 my $result_name = $result->att('name');
 if ($error_name && $result_name) {
  print "ERROR  : $error_name   \n";
  print "RESULT : $result_name \n";
 }
}