christmas

Question

1. is one allowed to give christmas gifts to his/ her coworkers/ employees? and if so, can one include a merry christmas card or a happy holidays card with the gift? 2. can one wish his/ her coworkers a merry christmas or happy holidays before they leave work on dec 24th? 3. can one participate in a christmas gift exchange? thank you rabbi; i know i can turn to you for the straight, cut and dry answer, as opposed to hearing other rabbis give the "frummie" reply without concern as to what halacha really states...