WP Nonces

Hi, I’m new to nonces and I’m using the code from https://www.garyc40.com/2010/03/5-tips-for-using-ajax-in-wordpress/

This uses wp_localize_script() to get the nonce into javascript, this is working fine and dandy but if I add an

alert(MyAjax.postCommentNonce);

in my javascript, the alert is the same for every page… Shouldn’t the nonce be different for every form/action?

I tried

wp_create_nonce( 'ajax-nonce-' . $post->ID; )

But some of the admin pages have the same page id so this doesn’t work.