Quoting Cheryle [TOG]:" I haven't used CS6. Are you having problems because it is set up differently or are have you not done masking yet and are trying to learn it?"
I'm trying to learn, I haven't had the need to do it so I haven't bothered learning.
In one of my couple pictures the girls eyes are closed, so I'm grabbing her eyes that are open from a similar picture into the one I like.
I quick selected the area ad dragged into the picture, I clicked the box at the bottom for masking. I selected the brush put the opacity to 100 and tried to paint the picture away. It didn't so I clicked edit in quick mask mode, did nothing.