Flash CS3 Professional.
RectangleObject.topLeftRadius
Read-only property; a float value that sets the radius of all corners of the rectangle (if RectangleObject.lockFlag is true) or that sets only the radius of the top-left corner (if RectangleObject.lockFlag is false).
To set this value, use document.setRectangleObjectProperty().
document.setRectangleObjectProperty(), RectangleObject.bottomLeftRadius, RectangleObject.bottomRightRadius, RectangleObject.lockFlag, RectangleObject.topRightRadius