loading content within category & pages

[jpopuk]

Hi, if I want to sepcify certain elements to a category:

 

<?php if (category_id == 3) { ?>Content for that paticular category.<?php } ?>

 

How would I set it for the pages within the category? - I can do it like so:

 

<?php if (category_id == 3 || page_id == 4 || page_id == 5) { ?>Content for that paticular category.<?php } ?>

 

But that means everytime I add a new page within that category I would have to manually add the new page_id to the list.

 

Is there a way to write it so it can display category_id and all pages within?

 

Any help would be great, thanks.

 

Paul