super(FIELD_WIDTH);  setHorizontalAlignment(JTextField.CENTER);  if (tip != null) { setToolTipText(tip); }  setEditable(editable);
this(true, tip);
    public SField (boolean editable,                   String  tip)    {        super(FIELD_WIDTH);        setHorizontalAlignment(JTextField.CENTER);        if (tip != null) {            setToolTipText(tip);        }        setEditable(editable);    }