gistfile1.pl

#!/usr/bin/env perl
use strict;
use warnings;

use feature ':5.10';

use LWP::UserAgent;
use HTML::TreeBuilder;

my $ua = LWP::UserAgent->new;
my $resp = $ua->get('http://www.usgbc.org/LEED/Project/CertifiedProjectList.aspx');

die 'Certainly no longer valid' unless $resp->is_success;

## custom Post Back
my $root = HTML::TreeBuilder->new_from_content( $resp->content );

## This should work.
$root->look_down( name => '__EVENTVALIDATION' )->look_up( '_tag' => 'form' );