How to Access Chat
There is a Facebook Chat app that you can use to chat with the people in your contact list in Facebook.
Tap the App Store on the iPhone main screen. Tap the Search button at the bottom of the screen and type Facebook Chat.
Tap the app when it appears on the screen. This app is completely free. Tap the Install button, and then enter your iTunes account username and password. Allow the app to finish downloading. This will only take a few minutes.
Tap the Facebook icon on the iPhone home screen to open Facebook. Click the Chat menu option to use Facebook Chat.
Use your fingers and swipe downward or upward to go through the list of contacts. To select a contact to chat with, tap their name. If a user has a green dot next to their name, they are currently online either on a computer or mobile device. If a contact has a half-moon icon next to their name, this user is idle.
An instant message (IM) window opens when you tap a contact’s name, addressed to them.
Enter your chat message and then click Send.
Return to your Facebook chat contacts by tapping the Chat button in the upper left-hand corner of the screen. Your buddy list returns and you can then send other people chat messages.
If you want to turn off Facebook Chat follow these instructions:
Open your Facebook Chat contact list from your iPhone. Click the Go Offline button in the upper right-hand corner of the screen. To go back online, simply tap the Go Online button