Well, I normally find code like this horribly annoying, so I wouldn't do any of the above.
I *hate* it when form code automatically moves me to the next field.
What happens if I made a mistake? What a pain to have to use the mouse to get back to the field and then carefully REMOVE the mistake before entering the correction. So inflexible. Maybe I want to add a letter at then end and *THEN* remove a character in the middle. With this kind of annoying crap I can't do that.
HAVING SAID ALL OF THAT...
I'm unaware of any "standard" in this area. But I would *assume* you'd just keep on going to the next input field. Your "groups" are artificial, anyway, so why make them more significant than they are? Besides, if you do otherwise, then the user must use the mouse (or hit TAB several times) to get to the *correct* next field.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.
Last edited by Old Pedant; 02-13-2013 at 04:23 AM..