Splitting Pages

I am using the copyblogger template, which has the code in it for breaking up long pages (not posts):
<?php wp_link_pages(); ?>

However, it doesn’t appear to be working. I have used the <!--more--> code, the HTML editor button and still no luck. Even tried <!--next--> to no avail.

Is there something I’m missing? Are there any suggestions for breaking up a long page?

Thanks for any help.

Dennis