MailChimp PHP Curl Add member to list

mailchimp.sample.php

<?php
$URL='http://us11.api.mailchimp.com/3.0/lists/LISTID/members';

$data = array("email_address"=>"xxX@sample.com","status"=>"subscribed","merge_fields"=>array("FNAME"=>"江","LNAME"=>"小屁","MMERGE3"=>"江小屁"));                               
$data_string = json_encode($data);

$ch = curl_init($URL);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    'Content-Type: application/json',
    'Content-Length: ' . strlen($data_string),
    'Authorization: apikey ad607dexxxxxxxxxxcc6f91b7xxxxxx6-us11')
);
//$status_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);   //get status code
$result=curl_exec($ch);
curl_close($ch);
echo $result;

?>