remove pio_ prefix in readme
diff --git a/README.md b/README.md
index 4bedecc..ee3ed17 100644
--- a/README.md
+++ b/README.md
@@ -99,7 +99,7 @@
 
 ```PHP
 // assume you have a book with ID 'bookId1' and we assign 1 as the type ID for book
-$response = $client->setItem('bookId1', array('pio_itypes' => 1));
+$response = $client->setItem('bookId1', array('itypes' => 1));
 ```