I don't mean to sound nit-picky or anything, but since I used to make the same mistake that I read many of you are making in this forum, I would like to point it out. The correct way to say "Peace be upon you" is either "Assalaam 'Alaykum" ( (salam)), or "Salaamun 'Alaykum." I see many people combining the two. Walaykum Salaam