Grishka, thanks for the interest, but don't worry about it. It's nothing to do with the code, that's fine and I know what I'm doing with that.

I just need to shift the whole display area to the left, or reduce the size of the display to include the whole picture, i.e. a fourth box that I need to put code in is off the right hand side of the screen.

I somehow need to find a way of clicking and dragging the contents to the right a bit so it will then show the missing box.