Having menu nav subs limit the number to display

I have this list page displaying only the 10 latest "articles"

http://65.99.232.147/articles/articles.php

What I need to do is to get the sub navigation also only display the last 10 articles as well.

How to do this? Here is my article nav code:

<li> <a href="/articles/articles.php">Articles</a> <ul>
<?php
list($categoryRecords, $selectedCategory) = getCategories(array(
'tableName' => 'articles',
'selectedCategoryNum' => '', // defaults to getNumberFromEndOfUrl()
'categoryFormat' => 'showall', // showall, onelevel, twolevel
));
?>
<?php foreach ($categoryRecords as $categoryRecord): ?>
<?php if ($categoryRecord['url']) { $categoryRecord['_link'] = $categoryRecord['url']; } ?>


<?php echo $categoryRecord['_listItemStart'] ?>
<a href="<?php echo $categoryRecord['_link'] ?>"><?php echo $categoryRecord['name'] ?></a>
<?php echo $categoryRecord['_listItemEnd'] ?>
<?php endforeach; ?>


</ul>
</li>
<!-- <li><span class="qmdivider qmdividery" ></span></li>-->