Gyazo php uploader

<?php
/**
 * Gyazo php uploader
 * 
 * @author		Neris Ereptoris <www.neris.ws>
 * @copyright	2010
 * 
 * @version		0.1
 * @link		http://neris.ws/
 */

//TODO: Error handling

$upload_dir_ulr = "http://example.com/g/";
$error_page_url = $upload_dir_ulr . "error.html";

$max_file_size = 1024 * 1024 * 4; // 4MB
$upload_dir_name = dirname(__FILE__) . "/";
$user_id = "insert your secret password here";


if ( !isset($_POST["id"]) || empty($_POST["id"]) )
{
	exit($error_page_url . "#id-not-found");
}

if ( $_POST["id"] != $user_id )
{
	exit($error_page_url . "#wrong-id");
}

if ( !isset($_FILES["imagedata"]["size"]) )
{
	exit($error_page_url . "#size-not-found");
}

if ( intval($_FILES["imagedata"]["size"]) > $max_file_size )
{
	exit($error_page_url . "#image-is-too-big");
}

$new_file_name = md5($_FILES['imagedata']['tmp_name'] . time()) . ".png";


if ( !move_uploaded_file($_FILES['imagedata']['tmp_name'], $upload_dir_name . $new_file_name) )
{
	exit($error_page_url . "#can-not-move-uploaded-file");
}

echo $upload_dir_ulr . $new_file_name;