How do I disallow specific page from robots.txt

Question

I am creating two pages on my site that are very similar but serve different purposes. One is to thank users for leaving a comment and the other is to encourage users to subscribe.

I don't want the duplicate content but I do want the pages to be available. Can I set the sitemap to hide one? Would I do this in the robots.txt file?

The disallow looks like this:

Disallow: /wp-admin

How would I customize to the a specific page like:

http://sweatingthebigstuff.com/thank-you-for-commenting

Answer 1

Disallow: /thank-you-for-commenting 

in robots.txt

Take a look at last.fm robots.txt file for inspiration.