Motorola Q

Got a question for all of you q users. Customer bought the q and synched with his outlook before doing a phonebook transfer. Obviously his outlook put all of his contacts from the computer into the q, but when I did the phone book transfer for him it erased the contacts put in with the synch. Now when he goes home and resynchs will it take all of his contacts that are now in his phone and add them to outlook, or will it replace the ones on the phone with the contacts from outlook. sorry if the stating of the question is a bit off, but you understand...right?