My iPhone was locked on portrait position. To unlock the screen, you need to double click on iPhone home button (one button facing you just below the screen). When the icon appears at the bottom, swipe it right one. The icon on the very left of the list is the lock and unlock button. Clock it once to unlock and once again to lock.
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SanDiegoTown & LosAngelesTown 
さち 
Official Bloguru Support 
木曽町田中屋豆腐 
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Pacific Software Publishing, Inc. 
Tetsuro Watanabe 
bokushi 
あさこ 
カワシマヒロキ（ひーさん）