Not quite there yet...
Thanks for that info.
I made those edits in the WA server validations dialog. However, I still can't seem to get this working. The form's behavior, when clicking submit, has not changed. I wonder if something is wrong with the server validation area, because when I go back to make a change, I have to re-enter everything from scratch. (In other words, nothing is pre-filled in the validations dialog.)
I'm attaching the latest version of the page. Hopefully something in it will stand out to you. I'm at a loss. :-)
(P.S. The online version is: contact_prayer_captcha.php)