CMultiFileUpload does not show selected files

Question

I am using CMultiFileUpload to upload multiple files. Using htmlOptions I can get multiple=>multiple to work, and multiple files gets stored in the database. However, after every selection from the input dialog box, there should be the name of the file, along with a remove button right beside it, like the user here has. In my case, this didn't show up. 'accept', 'duplicate','remove' and 'denied' also do not work.

Here is my view:

<?php
    $this->widget('CMultiFileUpload', array(
        'name'=>'files',
        'accept'=>'pdf',
        'duplicate'=>'File already selected!',
        'remove'=>'[x]',
        'htmlOptions' => array('multiple'=>'multiple'),
        'denied'=>'File is not allowed',
        'max'=>10
    ));
?>

These are the results: 1 and 2

Can anyone please point out where I went wrong?