Ahh! I'm starting to see how Zencart works now... Thank you so much for your help.

So I replaced
PHP Code:
<h1 id="advSearchResultsDefaultHeading"><?php echo HEADING_TITLE; ?></h1>
with:

PHP Code:
<h1 id="advSearchDefaultHeading">Search results for: <?php echo $sData['keyword']; ?></h1>
but the HTML output is only:

<h1 id="advSearchDefaultHeading">Search results for: </h1>

Any reason why it wouldn't get passed through?