Did you think you could avoid the inevitable? Here is how someone from New Hampshire would solve this using XML::Twig! I guess grantm will have more on the way you use XML::Simple ;--)

XML::Twig is quite appropriate here because it lets you specify quite easily that you only want to process header elements with a specific attribute name, and it will only load the relevant part of the document, instead of the entire thing.

#!/usr/bin/perl -w -l
use strict;
use XML::Twig;

my $name= live_free() or die;
my $t= XML::Twig->new( 
         twig_roots => { qq{header[\@name="$name"]} => \&print_content
+ },
                     );
$t->parse( \*DATA);

sub print_content
  { my( $t, $header)= @_;
    print join( "\n", map { $_->text } $header->children);
  }
                                       

sub live_free { return shift @ARGV; }

__DATA__
<?xml version="1.0"?>
<!-- This is XML for the Header Mapping -->
<map>
    <header name="ABCstatus">
        <act>WTO</act>
    </header>
    <header name="ABCevent">
        <act>WTO</act>
        <act>Call</act>
    </header>
    <header name="DEF-Call">
        <act>Call</act>
    </header>
    <header name="Unknown">
        <act>WTO</act>
        <act>SMS</act>
        <act>NetSend</act>
    </header>
</map>
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