How do you say how do you spell your name in Japanese?

"onamae wa nan desu ka" name what is ? <-- what it reads in english directly. but in japanese is 'what is your name?' or less polite: namae wa nan desu ka if you want someone elses name like their brother's or friend's you could say: brother == onisan no onamae wa nan desu ka. friend: tomodachi no onamae wa nan desu ka. no= shows posession -in this case- wa= marks the topic ka= question mark -- makes it a question.