No longer have ability to change artboard size...

Hi,

Hope you're well.

I'm working in CS6.

As I recall, you used to be able to change the artboard size when you first hit shift + O. There was a window for it at the top of the screen. Now,..for some reason that option is not there. It only gives me the ability to change the x and y coordinates. I have to double click the artboard tool to change the size of the artboard(s). How do I get back that ability?

Thanks!