Getter on layers width and heigth ?

Is it possible de use a getter to access widths and heigths of layers ?

For example : On an event, I want to set X and Y positions to a sprite in the middle of a layer. Like :

sprite.X = layer("myLayer").width / 2

sprite.Y = layer("myLayer").height / 2

Is it possible to do that ?

ViewportRight("layer") - ViewportLeft("layer")

ViewportBottom("layer") - ViewportTop("layer")

It works ! Thank you :)