Facebook is a social network site that functions as a forum for old friends, family members and coworkers to keep in touch. It also allows for social and business networking and developing new acquaintances. Facebook accounts are linked to your email address so when you receive a message or wall post, an email is sent to alert you. Sending a birthday greeting via Facebook will likely reach the recipient quickly and in a modern, trendy manner.

Log into your Facebook account by typing in your email address and password on the homepage.

View upcoming or current birthdays of your Facebook friends under the "Events" heading.

Click on a friend's name to navigate to their personal page.

Type in the comment box at the top of their page to write on their wall. You can also click on the "Send a message" link below their profile picture.

Write your birthday wishes. Facebook messages do not necessarily have to be proper, formal English with correct spelling. Don't be afraid to be informal and abbreviate. Facebook is a casual and friendly communications medium. Writing "Happy Bday to u," is considered appropriate lingo. If you prefer formal, grammatically correct writing, that is acceptable as well.

Click "Submit" or "Send message."