In my application, new accounts must be created by an administrator--users
will not create their own. Ideally, the user could then log on and specify
their own password question and answer, and the administrator doesn't even
know what that question and answer is.

I thought I could do this since Membership.CreateUser() includes an overload
that does not include question and answer arguments. However, when I use it,
I get the error "Invalid question-answer."

Can anyone suggest a better approach?

Thanks.