when using 'case:' you should place 'break;' after every case:
f.e:
Why are you using $_REQUEST[] (i don't why it is used for), i think you'ld better use $_GET[] as you send data through a link (<a href="index.php?language=Japanese&jpages=index">). To get the info, you should use $_GET['language'] and $_GET['jpages'], but forgive me if i'm wrong
Let me know if it works
Greetz,
UnrealEd