use WWW::Mechanize;
use WWW::Mechanize::Firefox;

# open firefox

my $firefox = WWW::Mechanize::Firefox->new(
create =>1,
activate=>1,
launch=>'/usr/bin/firefox',
  );

# stop timeout issues with firefox telnet

my $url='some url';
my $new_timeout=100000;
$firefox->repl->repl->client->{telnet}->timeout($new_timeout);
$firefox->get($url);

# log-in process

$firefox->click({xpath=>'//*[@id="signInLink"]'});
sleep 60;

my $username='username';
my $password='password';

# sign-in process

$firefox->form_id('sign-in-form');
$firefox->set_visible($username, $password );	
sleep 60;

$firefox->click({xpath=>'//*[@id="button-sign-in"]'});
sleep 30;
print "now logged-in\n";

# trying to get mechanize to use current mechanize::firefox session

my $user_agent_name='Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:39.0) Gecko/20100101 Firefox/39.0';

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

my $content = $agent->content();
print $content;