Customize the text message ringtone
•From the homescreen or from within the applications tray, touch Text messaging
•Press the Menu key (On the left with 4 squares)
•Touch Messaging Settings
•Touch Select ringtones (if option is greyed out, make sure Notifications is turned on / actived)
•Touch on any Notification ringtone to select and hear a sample.
•Press OK to set as notification ringtone