Computer game controller

I'm programming my Esplora board to be a game controller, I using the joystick to act like the 'arrow keys', but I can't figure out how to program one of the push buttons to be the 'control' key. I've tried 'ctrl' or 'control' and neither worked, so I was wondering if I was programming wrong or if its not possible to use the ctrl key.

zggy: push buttons to be the 'control' key. I've tried 'ctrl' or 'control' and neither worked,...

How ? ?

http://joshfire-tech.tumblr.com/post/65032568887/arduino-keyboard-emulation-send-real-key-codes

The Esplora works the same as the Leonardo.

Keyboard.press(KEY_CTRL_LEFT);