Set message notifications and message previews.
How to set message notifications
• Start the Message app and tap the menu button in the upper right corner of the screen, and select 'Settings > Notification settings.'
• Turn 'Notifications' on to receive notifications when new messages are received.
• When 'Show new message pop-ups' is turned on, a preview of newly received messages can be viewed in a pop-up.
• When 'Show new message content' is turned on, the content of newly received messages can be viewed in a pop-up.
• Select 'Notification sound' to change the notification sound for new messages.