Adding/Removing category links

This might not be the “cleanest” way to add this links, but I add them manually in index.php with

<div id="topnav">
 for a category
<a href="?cat=number">   category name   </a>   ~
or for a page
<a href="?page_id=number">   page title   </a>   ~ 

</div>

There must be some other way to add them automatically by displaying categories throught php in the loop, but can’t help much on that
hope that helps

I will give that a try. Thanks!