Hogwarts acceptance letter address

Im sending a Hogwarts acceptance letter to my HP-obsessed friend (her bday is coming up). So could someone tell me what exactly it says on Harry's acceptance letter so i have an idea of what i should do 4 my friend's? thx.
But there is another problem... in the book it says exactly where the person is in the building (ex. "The Cupboard Under the Stairs") so what should I do? I don't know where my friend will be in her house when her parents are getting the mail... help!