Silly(?) Question re: conditional lists

Hi,
I'm creating a Spanish-language version of a site for a client, and have created fields where the translated content goes ("title_SP", "content_sp", "uploads_sp", etc.). I also created a mechanism to set cookies based on language preference, etc. and have all that working.

My main question pertains to the menus - I'm using nested-list drop-down menus (jquery) that get auto-generated by creating a list viewer for each category. Since the client does not want to translate each and every page of the site into Spanish, they only want the pages that *are* in Spanish to appear on the top nav. Other than hand-coding a custom menu list, is there a way to check if a field (such as "name_sp") exists for each record within a category, and only spit out a list with the results that do?

I've looked through the forum and my CMSB cookbook, and can't seem to find an answer... it seems like it should be simple, but I'm stuck. Thanks in advance for your help!
-Dan

P.S. Below is the code I'm using to generate the category lists. I'd like it to only produce results for records where there is actual data existing for "name_sp":

<?php
list($about_usRecords, $selectedTestRecord) = getCategories(array(
'tableName' => 'about_us',
));
?>
<?php foreach ($about_usRecords as $categoryRecord): ?>
<?php echo $categoryRecord['_listItemStart'] ?>
<?php if ($categoryRecord['_isSelected']): ?><b><a href="<?php echo $categoryRecord['_link'] ?>"><?php echo $categoryRecord['name_sp'] ?></a></b>
<?php else: ?><a href="<?php echo $categoryRecord['_link'] ?>"><?php echo $categoryRecord['name_sp'] ?></a>
<?php endif; ?>
<?php echo $categoryRecord['_listItemEnd'] ?>
<?php endforeach; ?>