Disabling comments in some posts and pages

Hi,

I have been a user of WordPress for a long time now, and remember in older versions there was an option (when you were creating a post or page) to disable comments on that particular post/page. However, recently on some of my new sites I can’t seem to find this option (WordPress 3+). I have resorted to deleting the comment code in page.php and single.php.

Can anyone help?

Thanks