Where is the Thanks button

Where is the Thanks button?
I'd like to add a Thanks for an answer I found but there is no Thanks button anywhere on the page. I saw on a "tour" page that it is supposed to be "under the Post". I am logged in.

I guess that just proves how new I am here!

Thank-you.

Bottom left of the post you should see a thanks link as seen in the attached screen shot.

Attachment 11312

Thanks - yes, I do see that word "Thanks" (was looking for an actual button instead of a link).
However, in the post where I wanted to give a Thanks, that link is not present. I wonder if that post is considered to old to be thanked. It is dated December, 2010. (I attached a screenshot of the bottom of the post).

I'm not sure why the thanks option is gone for that post. I know ChrisW is still alive and well on these forums, so perhaps it is limited due to the age of the post. Do you see the thanks option for recent posts?

Yes, I do see the Thanks on one dated March, 2015. I also see it on one dated Dec., 2009.
Well, it's a mystery. Thanks :-) for your quick response.