Oops. That should have read, "Both of these experiments were done with INVALID card numbers."

Unfortunately, the flyertalk web site seems to have developed a bug in the past week or so where it treats me as being logged out all the time, preventing me from editing a previous posting (but it allows me post, if I reenter my user name password after submitting the posting). So, I apologize for making such a simple correction in the form of a new message. (I'm able to edit my posts agiain as of April 15, 2012.)