Template parsing question

Here's the contents of /modules/boonex/sounds/templates/base/thumb.html

<div class="sys_file_search_pic" style="background-image: url('__imgUrl__');">
    <bx_if:admin>
        <div class="bx_sys_unit_checkbox">
            <input type="checkbox" name="entry[]" value="__id__"/>
        </div>
    </bx_if:admin>
    <a href="__fileLink__"><img src="__spacer__"></a>
</div>

That __id__ key only parses when it is within the bx_if:admin tags.  Anybody know what I have to do to be able to use it as an id for the main div, so when it parses the div will have a unique id?  I tried a few things in BxBaseSearchResultsSharedMedia.php with no luck. 

I want a random background image for sounds thumbs as shown HERE but since every div has the same id, the background image is the same for each thumb. ( Refreshing the page will change the bg image)  The only way to get this to work right, is for each thumb div to have a unique ID.

edit BxBaseSearchResultSharedMedia.php at line 330 add this

'ID' => $iId,

so it will look like this

$aUnit = array(

            'imgUrl' => $this->getImgUrl($sIdent),

            'spacer' => getTemplateIcon('spacer.gif'),

            'fileLink' => $sFileLink,

            'ID' => $iId,

            'bx_if:admin' => array(

                'condition' => $this->bAdminMode,

                'content' => array('id' => $iId)

            )

        );

Use __ID__ in template.

Good luck :)

 That's one of the things I already tried.  It doesn't work.   When the page is served up, it remains as __ID__, not the actual id number of the file.

OK... it's another case of self-inflicted injury. 'ID' => $iId, works if I out it in the correct file.  Seems as though about 2 years ago, I modified this class in my templates /scripts/BxTmplSearchResultsSharedMedia.php file, and that's where this has to go.

Now it all works.   I just need to design some better looking background images... not real happy with my first try.