How do i get people's screennames with only knowing their first and last name?

Im tryin to find someone i went to school with and only can remember his name. no one else has his s/n and i want to try and find him. anyone know how? for AIM

How do i get people's screennames with only knowing their first and last name?
ITs hard to get the screen name from the first and last name. They might not be using their first and last name to create the screen name. Better you ask them for their screen name