You have an ability to interact with your friends via wall-2-wall function. Do not forget that your posted messages can be read by friends of a person on whose wall you have written even if your privacy settings related to news feed prohibit notification about your writing on a wall activity.
1. Open your friend’s profile page.
2. Input your message in the Wright field.
3. In order to leave the message on the wall, snap on the Post knob.