Remove a widget on specific posts

Is there a way to remove a widget from one category?

I want it to show up on all categories except one specific category.

This is the widget area I want to remove on the category <?php if ( !function_exists(‘dynamic_sidebar’) || !dynamic_sidebar(‘sidebaradvertisement’) ) : ?><?php endif; ?>

any help would be awesome thanks.

This is my sidebar.php

<?php include(TEMPLATEPATH.’/searchform.php’); ?>

<?php if ( !function_exists(‘dynamic_sidebar’) || !dynamic_sidebar(‘sidebaradvertisement’) ) : ?><?php endif; ?>
<?php if ( !function_exists(‘dynamic_sidebar’) || !dynamic_sidebar(‘sidebar’) ) : ?><?php endif; ?>