www.wysiwygwebbuilder.com

In a recent wwb update there was an option to place the page in the centre of the work space and there was a grey colour to the left and right of this.
I have installed wwb on a new PC and can't for the life of me find this option.
I'm sure I didn't dream it so can someone tell me where it is and stop me from going crackers?!!
Thanks.

Menu -> View -> Design Layout

Of course, I'm an idiot.
I was looking everywhere else but there!
Thanks Pablo.