Learning Japanese, need some help

I'm trying to learn some Japanese, but I'm having some trouble with question sentences.
If you are to ask someone what their telephone number is, and you want to include their name, how would it turn out?
Would it be:
"Name" no denwa bango wa nan desu ka?
or:
denwa bango no "name" wa nan desu ka?

Or am I wrong on both of them? :)

The question is supposed to be directly to the person who's telephone number I am asking.
And how would the sentence be if I asked someone for another person about someones telephone number? (ex: I ask person X, "what is Y's telephone number").

Thanks for all help :)

Option number 1 is correct on both occasions

Yes, as naes said, when you ask person X, Y or Z,
"X no denwa bango wa nan desu ka?" is always correct.

In a question for a telephone number, "nan-ban" is more natural.

A simple way to ask someone directly
: ({Name} san,) o-denwa(-bango) wa nan-ban desu ka?
A more polite way to ask someone directly
: {Name} san, o-denwa-bango wo ukagat-temo yoroshii desu ka?"
= Dear {Name}, is it OK for me to hear your telephone number?

A usual way to ask another person
: {Name} san no denwa-bango wa nan-ban desu ka?

I forgot to use "-" between {name} and "san."