> Exactly---but this sort of automatic unlimited UNDO capability is a
> wonderful thing for increasing interactivity. The higher bandwidth
> of interaction you want to achieve, the more useful it becomes.
But, how do you get the database at the other end to roll back
in sync with the browser. At the very least the browser would have
to send a message to the server to roll-back each step. This is well
outside the current HTTP/fill-out forms mechanism. Worse, I can't
see how its possible to roll-back the state in all cases.