Morgans wrote:

Set up the online "Specific Suite Booking", so that the confirmation is
not
guaranteed until an e-mail is sent back, say, 15 minutes later. That will
give you time to check with the phone booking, and send back to the online
guy saying, "yep you have it for sure". Be sure to put a privacy clause
saying that no unsolicited e-mails will be sent, and that no one else will
have access to their e-mail address.

And if they enter an incorrect email, or some other problem prevents this
email from succeeding?

At a minimum, you'll need a "check back with us" URL. And this still leaves
you exposed if someone changes their mind and then says "oh, I didn't
receive your email".

It's a classic: http://www.nist.gov/dads/HTML/byzantine.html

- Andrew