[php]uploadify无法上传文件初学

本人初学uploadify上传，使用给的demo无法将文件上传到uploads文件夹内
请各位大神给予指导
index.php

    
Uploadify Demo
            upload     

uploadify.php 上传处理文件
/*
Uploadify
Copyright (c) 2012 Reactive Apps, Ronnie Garcia
Released under the MIT License http://www.opensource.org/licenses/mit-license.php
*/

// Define a destination
$targetFolder = '/uploads'; // Relative to the root

$verifyToken = md5('unique_salt' . $_POST['timestamp']);

if (!empty($_FILES) && $_POST['token'] == $verifyToken) {
$tempFile = $_FILES['Filedata']['tmp_name'];
$targetPath = $_SERVER['DOCUMENT_ROOT'] . $targetFolder;
$targetFile = rtrim($targetPath,'/') . '/' . $_FILES['Filedata']['name'];

// Validate the file type$fileTypes = array('jpg','jpeg','gif','png'); // File extensions$fileParts = pathinfo($_FILES['Filedata']['name']);if (in_array($fileParts['extension'],$fileTypes)) {    move_uploaded_file($tempFile,$targetFile);    echo '1';} else {    echo 'Invalid file type.';}

}
?>