Update Subscriber (put)

<?php
//example PHP code to update a subscriber
//set values of person to update
$put_params['apiKey']="APIKEY_HERE";
$put_params['id']="SUBSCRIBERID_HERE";
//Optional fields commented out below:
//$put_params['email']="example@email.com";
//listId can be one listid, or for multiple lists, pass a comma-delimimted list of listIds
//$put_params['listId']="1";
//$put_params['listId']="1,2,3,4"; 
//$put_params['firstname']="FIRSTNAME_HERE";
//$put_params['lastname']="LASTNAME_HERE";
//$put_params['mobile_phone']="9999999999";
//$put_params['email_type']="1";
//$put_params['unsubscribe']="0";
//$put_params['sms_unsubscribe']="0";
//$put_params['customfields']='{"custom1": "CUSTOMFIELD_VALUE_HERE", "custom2": "CUSTOMFIELD_VALUE_HERE"}';

$url = 'http://apidomain.com/api2/subscriber';

//Puts this using CURL
$curl = curl_init($url);

curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "PUT"); 
curl_setopt ($curl, CURLOPT_CONNECTTIMEOUT, 100);
curl_setopt($curl, CURLOPT_POSTFIELDS,http_build_query($put_params));

$result = curl_exec ($curl);
curl_close ($curl);
echo $result;

//Parse the json to get return values. 
$parsed_result = json_decode($result,false);

echo "<br><br>Status: $parsed_result->status";
echo "<br>Message: $parsed_result->message";
echo "<br>Error Code: $parsed_result->errorcode";
echo "<br>Error Message: $parsed_result->errormessage";
echo "<br>Subscriber Id: ";
echo $parsed_result->data->id;
echo "<br>Subscriber Email:";
echo $parsed_result->data->email;
echo "<br>Subscriber First Name:";
echo $parsed_result->data->firstname;
?>