displaying one category only, on specific pages

hi all.

i am in desperate need of some help.

i used wordpress to create a small cms site for a client. all is well except for the fact that he wants to display different links in the sidebars depending on what page is shown.

i am trying to use the is_page function to display a category. for some reason it is not recognising what page it is on thus the category does not get displayed.

basically i am displaying a category on the PAGE in a small sidebar on the page like so

<div id=”whitepapers”>

<?php
query_posts(‘cat=26’);
?>
<?php if (have_posts()) : ?>
<?php while (have_posts()) : the_post();?>

<div class=”post” id=”post-<?php the_ID(); ?>”>
<h2>” rel=”bookmark” title=”Permanent Link to <?php the_title(); ?>”><?php the_title(); ?></h2>

<?php the_content(‘Read the rest of this entry »’); ?>
</div>
<?php endwhile; ?>
<?php else : ?>
<?php endif; ?>

</div>

i now need to be able to detect what page it is, either by slug name or page id and then display a different category. for example, on the applications page i want to show a category in the sidebar that has links to different application data. then on the whitepapers page i want to show a category that has links to technical whitepapers etc.

can anyone here help me out. i have been at this for hours, googled to death and am not finding anything that is working.

Thank you

Mark…