Continue writing the next sentence.

How to find old friends online
Brainstorm a list of information that you know about the person.
The more information you have, the easier it will be to locate your friend. Think about when and where you knew the person, and who else you knew at the same time.
Write down as many of the following pieces of information about the person as you can recall. It is not necessary to have all of this information, but the more you have to work with, the better your chances are of finding your friend.