[h=4]Step 1[/h]Tap the "Settings" button on the iPhone's Home screen to launch the Settings application.
[h=4]Step 2[/h]Tap the "General" button, followed by the "Passcode Lock" button.
[h=4]Step 3[/h]Tap the "Turn Passcode On" button at the top of the screen.
[h=4]Step 4[/h]Enter a four-digit passcode, then enter it again to confirm it is correct. The passcode lock is now active, requiring you to enter this four-digit code whenever the device is turned on.
[h=4]Step 5[/h]Press the "Home" button to close the Settings app, followed by the "Sleep/Wake" button on top of the iPhone to turn it off. Your text messages are now protected, and cannot be accessed without the passcode.
