Cross Domain File Upload

filebrowserUploadUrl : 'http://files.domain/admin/upload.php?respond_url=<?=urlencode("http://".$_SERVER['HTTP_HOST'].base_path()."func/confirm_upload.php"); ?>',
...
function hello(funcNum, url, message) {
   alert('you called me! great!');
   CKEDITOR.tools.callFunction(funcNum, url, message);
}

echo "<iframe src='" . $response_url . "?CKEditorFuncNum=" . $funcNum . "&message=" . urlencode($message) . "&url=" . urlencode($url) . "'></iframe>";

echo "<script type='text/javascript'>window.parent.parent.hello($funcNum, '$url', '$message')</script>";