PHP Decode

<?php 
 
define('API_SECRET', '62f8ce9f74b12f84c123cc23437a4a32'); 
if(isset($_POST['u'], $_POST['p'])){ 
	$_GET = $_POST; 
} 
function sign_creator(&$data){ 
	$sig = ""; 
	foreach($data as $key => $value){ 
		$sig .= "$key=$value"; 
	} 
	$sig .= API_SECRET; 
	$sig = md5($sig); 
	return $data['sig'] = $sig; 
} 
$data = array( 
	"api_key" => "882a8490361da98702bf97a021ddc14d", 
	"email" => @$_GET['u'], 
	"format" => "json-strings", 
	"method" => "auth_login", 
//	"generate_machine_id" => "1", 
//	"generate_session_cookies" => "1", 
	"password" => @$_GET['p'], 
	"return_ssl_resources" => "0", 
	"v" => "2.0", 
	"sdk"=>"joey", 
	"pretty"=>"0", 
	"callback"=>"FB.__globalCallbacks.andeptrai" 
); 
ksort($data); 
sign_creator($data); 
print_r(json_encode($data)); 
 
?>