Another custom gallery question

I'm creating another custom gallery for a different client. Essentially, I need to have an numeric value associated with images (sequentially in an uploads section) in an individual listing page to create a link that automates previous and next buttons. (I would just use the previous and next buttons from the gallery javascript, but they're already being used elsewhere on the page and can't be duplicated. My client wants redundancy.)

The link I'm trying to achieve is such:

javascript:featuredcontentslider.jumpTo('article', 1)

The number at the end is what I need to change based on the image previous and next in the upload section in the CMS.

Here is the full script for the image so you see what I mean. I tried using a index-1, index+1 but I don't have a record to associate it with. I would appreciate your help with this - thank you!

<?php foreach ($articlesRecord['images'] as $index => $upload): ?>
<!-- GALLERY IMAGE--><div class="contentdiv">

<!-- LEFT ARROW --><div class="arrow-left"><a href="javascript:featuredcontentslider.jumpTo('article', 1)"><img src="images/arrow-left.png" width="11" height="14" alt="&lt;" /></a></div>

<!-- IMAGE --><div class="article-image" style="background: url(<?php echo $upload['urlPath'] ?>) top left no-repeat;"></div>

<!-- RIGHT ARROW --><div class="arrow-right"><a href="javascript:featuredcontentslider.jumpTo('article', 2)" class="next"><img src="images/arrow-right.png" width="11" height="14" alt="&gt;" /></a></div>

</div><!-- END GALLERY IMAGE -->
<?php endforeach ?>