use strict;
use warnings;
use HTML::TreeBuilder;
use WWW::Mechanize;
use URI::Escape;

my $agent = WWW::Mechanize->new();

$agent->get('http://www.usgbc.org/myUSGBC/Members/MembersDirectory.aspx?PageID=2011&CMSPageID=140');
$agent->form_name('frmMemberDirectory');
$agent->field('ddlCategory', '');
$agent->field('ddlState', '');
$agent->field('ddlCountry', 'US');
$agent->field('txtCompanyName', '');
$agent->click('btnSearch');

my $node = HTML::TreeBuilder->new();
$node->parse( $agent->content );

my $val_id = $node->find_by_attribute( id => '__EVENTVALIDATION');
my $validation = $val_id->attr('value'); 
my $state_id = $node->find_by_attribute( id => '__EVENTVALIDATION');
my $view_state = $state_id->attr('value');

$validation = uri_escape( $validation );
$view_state = uri_escape( $view_state );

my $id = '__EVENTTARGET=dgMembers%24ctl01%24ctl11&__EVENTARGUMENT=&__VIEWSTATE='.
		 $view_state .
		'&txtCompanyName=&ddlCategory=&ddlState=&ddlCountry=US&__EVENTVALIDATION='. 
		$validation;

$agent->post('http://www.usgbc.org/myUSGBC/Members/MembersDirectory.aspx?PageID=2011&CMSPageID=140',
			Content => $id);
print $agent->content();