So I'm scraping a site that I have access to via HTTPS, I can login and start the process but each time I hit a new page (URL) the cookie Session Id changes. How do I keep the logged in Cookie Session Id?

#!/usr/bin/perl -w
use strict;
use warnings;
use WWW::Mechanize;
use HTTP::Cookies;
use LWP::Debug qw(+);
use HTTP::Request;
use LWP::UserAgent;
use HTTP::Request::Common;

my $un = 'username';
my $pw = 'password';

my $url = 'https://subdomain.url.com/index.do';

my $agent = WWW::Mechanize->new(cookie_jar => {}, autocheck => 0);
$agent->{onerror}=\&WWW::Mechanize::_warn;
$agent->agent('Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.3) Gecko/20100407 Ubuntu/9.10 (karmic) Firefox/3.6.3');
$agent->get($url);

$agent->form_name('form');
$agent->field(username => $un);
$agent->field(password => $pw);
$agent->click("Log In");

print "After Login Cookie: ";
print $agent->cookie_jar->as_string();
print "\n\n";

my $searchURL='https://subdomain.url.com/search.do';
$agent->get($searchURL);    

print "After Search Cookie: ";
print $agent->cookie_jar->as_string();
print "\n";

The output:

After Login Cookie: Set-Cookie3: JSESSIONID=367C6D; path="/thepath"; domain=subdomina.url.com; path_spec; secure; discard; version=0

After Search Cookie: Set-Cookie3: JSESSIONID=855402; path="/thepath"; domain=subdomain.com.com; path_spec; secure; discard; version=0

Also I think the site requires a CERT (Well in the browser it does), would this be the correct way to add it?

$ENV{HTTPS_CERT_FILE} = 'SUBDOMAIN.URL.COM'; ## Insert this after the use HTTP::Request...

Also for the CERT In using the first option in this list, is this correct?

X.509 Certificate (PEM)
X.509 Certificate with chain (PEM)
X.509 Certificate (DER)
X.509 Certificate (PKCS#7)
X.509 Certificate with chain (PKCS#7)