Centering a circle on a layer
Trying to do something very simple, or so I thought.
I have a background square and now I want to put a smaller circle of a fixed size right in the middle. I'm using the eliptical marque tool of a fixed size to create the circle and can place it on the square but can't find a way to exactly centre it. If I use the move tool, all the align and distribute tools do nothing. This is all within the same layer - no other layers at all on the image.

