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

        <lNewState> is a logical value that indicates whether the check box
        should be checked or not.  Set to true (.T.) to check the box or
        false to uncheck the box.  If omitted, the check box state will
        toggle to its opposing state.

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