Where is the problem

I am working on a website where i need to upload multiple thumbnail simultaneously.. when I am uploading single thumbnail its working properly but when it comes to multiple thumbnail nothing works...

here is the code..

Here is upload.php code..

 

Read this: http://us2.php.net/manual/en/features.file-upload.multiple.php

If you want to see what you're getting do:

echo "<pre>";print_r($_FILES);echo "</pre>";

PHP: