制作PHP上传表单：“move_uploaded_file”与wordpress一起使用

I have a picture upload form powered with dropzone.js (http://www.dropzonejs.com/):

<form action="<?php bloginfo('template_url'); ?>/frameworks/dropzone/upload.php" class="dropzone" style="margin: 100px; border:solid; "></form>

This works fine! But the upload.php file won't properly upload my images...

$ds          = DIRECTORY_SEPARATOR;  //1

$storeFolder = "uploads";   //2

echo "√ Launched upload.php";

if (!empty($_FILES)) {

    $tempFile = $_FILES['file']['tmp_name'];          //3             

    $targetPath = dirname( __FILE__ ) . $ds. $storeFolder . $ds;  //4
    $targetFile =  $targetPath. $_FILES['file']['name'];  //5

    echo "<br>Target Path: ".$targetPath;
    echo "<br>Target File: ".$targetFile;

    move_uploaded_file($tempFile,$targetFile); //6
    echo "<br>√ move_uploaded_file";
 }

The move_upload_file doesn't seem to work properly...... Any hints?

Errors: Warning: move_uploaded_file(/var/www/vhosts/jtc.ae/httpdocs/pre/wp/wp-content/themes/Amazing_japan_HP/frameworks/dropzone/uploads/kimono's at JTC.jpeg): failed to open stream: Permission denied in /var/www/vhosts/jtc.ae/httpdocs/pre/wp/wp-content/themes/Amazing_japan_HP/frameworks/dropzone/upload.php on line 25 Warning: move_uploaded_file(): Unable to move '/tmp/phpDXnFKq' to '/var/www/vhosts/jtc.ae/httpdocs/pre/wp/wp-content/themes/Amazing_japan_HP/frameworks/dropzone/uploads/kimono's at JTC.jpeg' in /var/www/vhosts/jtc.ae/httpdocs/pre/wp/wp-content/themes/Amazing_japan_HP/frameworks/dropzone/upload.php on line 25