Skype status PHP script for use with AJAX

skype_status.php

<?php
header('Content-type: application/json');

if ( array_key_exists('username', $_GET) )
    $user = $_GET['username'];
else
    $user = "";

$curl = curl_init("http://mystatus.skype.com/${user}.num");
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

$n = curl_exec($curl);
if ( !is_numeric($n) )
    $n = 0;

$s = array(1 => 'offline', 2 => 'online', 3 => 'away', 5 => 'do_not_disturb');

if ( array_key_exists($n, $s) )
    $status = $s[$n];
else
    $status = 'unknown';

echo json_encode(array("username" => $user, "status" => $status));
curl_close($curl);
?>

hi