Mailchimp plugin for 3.8.7: What do I need to modify?

[jGas]

Hi, this code is working great on the site where I found it, http://www.bestrecipes.com.au/site/mailchimp.html, that is running 3.8.3 but not on my board that is 3.8.7.

This is the plugin code:

require_once 'mailchimp/MCAPI.class.php'; // location of API file, relative to
forum root directory
$apikey= 'myapikey-us2'; // your API key
$listId = '3af3706004321'; // the list ID

// Connect to the MailChimp server
$api = new MCAPI($apikey);

if ($api->errorCode!=''){

// an error occurred while logging in, errors commented in HTML
echo "<!-- code:".$api->errorCode."-->";
echo "<!-- msg :".$api->errorMessage."-->";
die();
}

// get current user details
$my_email=($vbulletin->userinfo['email']);

// profile fields are best set up as single-selection radio buttons,
// use multiple profile fields for interest groups and mail format

// vBulletin profile field options:
// use Yes/No options (use HTML/Text for mail format)
// Set default: Yes
// Field Required: No but display at registration
// Field Editable by User: Only at registration
// Handle unsubscribes and profile updating via links in mailings, or another
API plugin

$news1=($vbulletin->userinfo['field12']); // add custom profile field number
for interest group 1
// $news2=($vbulletin->userinfo['field14']); // add custom profile field
number for interest group 2
// $news3=($vbulletin->userinfo['field15']); // add custom profile field
number for interest group 3

$newsformat=strtolower(($vbulletin->userinfo['field13'])); // profile field
number for mail format, html or text

// add interest group names, note trailing commas in all but last one - a
quick hack but it works!

if ($news1=='Yes') {
$interests='Interest group name here,';  // escape apostrophes in name with a
backslash i.e. What\'s On
}

if ($news2=='Yes') {
$interests.='Interest group name here,';
}

if ($news3=='Yes') {
$interests.='Interest group name here';
}

$merge_vars = array('INTERESTS'=>$interests);
// only send request if subscribed to at least 1 newsletter
if ($news1=='Yes' || $news2=='Yes' || $news3=='Yes') {
$retval = $api->listSubscribe( $listId, $my_email, $merge_vars, $newsformat
);
}

if (!$retval){
        // return error codes, commented in HTML
echo "<!--Newsletter failed!-->";
echo "<!--\tCode=".$api->errorCode."-->";
echo "<!--\tMsg=".$api->errorMessage."-->";
// email backup for API failures, multiple subscribes etc.
$to      = 'info@musicadigitale.net';
$subject = 'Newsletter API failed';
$message = "The following member details were not subscribed by the API:\n";
$message .= "Email: $my_email\n";
$message .= "Interest groups: $interests\n";
$message .= "Mail format: $newsformat\n";
$message .= "Error message: " . $api->errorMessage . "";
$headers = "From: MailChimp API <adminemail@domain.com>\n";
$headers .= "Reply-To: adminemail@domain.com\n";
$headers .= "X-Mailer: Your forum name\n";
mail($to, $subject, $message, $headers);
} else {
    echo "<!--Newsletter subscribed ok-->";
}

Many thanks for your time