<oRadioButto>:select([<lNewState>]) --> self

        <lNewState> is a logical value that indicates whether the radio
        button should be selected or not.  Set to true (.T.) to select the
        button or false (.F.) to deselect the button.  If omitted, the radio
        button state will toggle to its opposing state.

        select() is a method of the RadioButto class that is used for
        changing the state of a radio button.  Its state is typically changed
        when the space bar or one of the arrow keys is pressed or the mouse's
        left button is pressed when its cursor is within the radio button's
        screen region.

        This message is meaningful only when the RadioButto object has input
        focus, or when the radio button is a member of a Group object that
        has input focus.