part of a text field bold - possible?

[Anonymous]

while($row = mysql_fetch_array($result))	{
        $data = $row['page_data'];
        echo str_replace($search_term, '<strong>' . $search_term . '</strong>', $data);
}

Of course, you should really make your search work with more than one search term. Consider using full-text search instead (refer to the docs).