Widget.newbutton -- Width/height Required, Or Not?

In the docs for widget.newButton it says this:

width, height (required)

Numbers. This is the width/height of the Button. If you are using Single frame button creation set these to the width/height of your image. If you are using 9-Piece Button Creation (default) you may set these to any width/height and the button will scale accordingly.

 

But this code seems to work just fine:

[lua]

 

    local horseButton = widget.newButton

    {

        id = “choose horse”,

        isEnabled = false,

        onRelease=buttonPressed,

        defaultFile = “images/btn-chooseyourhorse.png”,

        overFile = “images/btn-chooseyourhorse-pressed.png”

    }

[/lua]

It shows the button using the size of the image. I just don’t want to code something and have a “fix” down the line break things.

Required? Optional?

Jay