Once you have composed a message and chosen the recipients, choose the "Post to Wall" option and you will see options to Require Sign Off and Allow Comments.
1. Click the Message icon found in the left side menu.
2. Click the Compose icon found in the top header.
3. Write a message in the Message Box.
4. Check the mark next to the group(s) or individual(s) you would like to share the message with.
5. Then select Post to Wall.
6. You can Require Sign Off on the wall post or Allow Comments by checking the box next to either option (this is not required).
7. Once you have completed all the steps above, click Send Message.