Lock / unlock Screen Portrait orientation mode - Apple® iPhone® 4S

1. From the main screen, press the menu button twice quickly to access the recently used applications screen.
   
2. From the recently used applications screen, drag the bottom of the screen to the right.
   
3. Select the Portrait Orientation symbol to lock / unlock screen portrait orientation.
   When lock symbol is present, the screen is locked into portrait orientation mode.
   
4. Press the menu button to exit.