Problème upload image via tinymce

<script>
    tinymce.init({
        selector: "textarea#text",
        language: 'fr_FR',
        theme: "modern",
        height: 350,
        browser_spellcheck : true,
        plugins: [
             "advlist autolink link image lists charmap print preview hr anchor pagebreak",
             "searchreplace wordcount visualblocks visualchars code fullscreen insertdatetime media nonbreaking",
             "save table contextmenu directionality emoticons template paste textcolor codesample filemanager"
       ],
       codesample_languages: [
        {text: 'HTML/XML', value: 'markup'},
        {text: 'JavaScript', value: 'javascript'},
        {text: 'CSS', value: 'css'},
        {text: 'PHP', value: 'php'},
        {text: 'Ruby', value: 'ruby'},
        {text: 'Python', value: 'python'},
        {text: 'Java', value: 'java'},
        {text: 'C', value: 'c'},
        {text: 'C#', value: 'csharp'},
        {text: 'C++', value: 'cpp'}
    ],
       content_css: "css/content.css",
       toolbar: "insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image | print preview media fullpage | forecolor backcolor emoticons | codesample", 
        paste_data_images: true,
        images_upload_url: 'post.php',
        automatic_uploads: true
    }); 
</script>

<?php
  $accepted_origins = array("http://localhost", "http://192.168.1.1", "http://example.com");
  $imageFolder = "../../images/";
  reset($_FILES);
  $temp = current($_FILES);
  if(is_uploaded_file($temp['tmp_name'])){
    if(isset($_SERVER['HTTP_ORIGIN'])) {
      if(in_array($_SERVER['HTTP_ORIGIN'], $accepted_origins)) {
        header('Access-Control-Allow-Origin: ' . $_SERVER['HTTP_ORIGIN']);
      } else {
        header("HTTP/1.0 403 Origin Denied");
        return;
      }
    }
    if(preg_match("/([^\w\s\d\-_~,;:\[\]\(\).])|([\.]{2,})/", $temp['name'])) {
        header("HTTP/1.0 500 Invalid file name.");
        return;
    }
    if(!in_array(strtolower(pathinfo($temp['name'], PATHINFO_EXTENSION)), array("gif", "jpg", "png"))) {
        header("HTTP/1.0 500 Invalid extension.");
        return;
    }
    $filetowrite = $imageFolder.$temp['name'];
    move_uploaded_file($temp['tmp_name'], $filetowrite);
    echo json_encode(array('location' => $filetowrite));
  } else {
    header("HTTP/1.0 500 Server Error");
  }
?>