password protecting a category

I found a article on how to password protect a category (http://www.atlanticbt.com/blog/wordpress-password-protected-templates/, but I am not sure where to put the code. Do I put in my archive.php file? I’m not sure if this is even what I’m looking for.

What confuses me even more is this line of code
<?php query_posts( ‘post_type=abt_member’)

I’m not sure what my post type is?