Help with a tutorial involving mental ray

Hi iv just started using maya in prep for a game design course im doing. Im enjoying it but now im stuck.

Im doing this tutorial http://www.cgonlinetutorials.com/tutorials/joy-stick-page8.html making a joystick, it told me to make an area light and enable ray trace shadows and use light shape in mental ray. but it is blank and wont let me enable use light shape.

Can anyone help me enable it, any help would be great.