I am creating an ajax uploader with mootools. When I remove the ajax and simply upload the form I get $_FILES with the file data present. But when I use the ajax version, the $_FILES super global is empty. Every other part of the form is present. It acts as if it does not send the image at all but only in the ajax version. Any help is appreciated. Thanks!

<form id="uploadphoto_pod" action="upload.php" enctype="multipart/form-data" method="post">
<input type='file' id='uploadphoto' name='uploadphoto'/>
<input type="submit" class="submit" name="add_product" value="Upload" />
  </form>
   <div id="response"><!-- Ajax Response --></div>
<script type="text/javascript">
 window.addEvent('domready', function(){
$('uploadphoto').addEvent('submit', function(e) {
    //Prevents the default submit event from loading a new page.
    e.stop();
    //("this" refers to the $('uploadphoto') element).
    this.set('send', {onComplete: function(response) {
        $('response').set('html', response);
    }});
    //Send the form.
    this.send();
});
});
   </script>