increment/decrement button issue in react app

Actually i want to show this Names in a sequence but whenever i click increment button the order ( in useState ) increment by 1 but when i click decrement button first time the order again increment by 1 and then is less than one.

function func() {
  let [getVal, setVal] = useState({
    alerts: "no alerts",
    order: 0,
  });
  
  let Names = [
      "Default",
      "Evil laugh",
      "classic alarm",
      "Pause",
      "intro music",
      "Got item",
      "Old bounce",
      "bark",
      "alarm tone",
    ];

  function slider(e) {
    let { order } = getVal,
    value = e.target.id,
    total = Names.length; 
    if (value === "up" && order !== total - 1) {
      setVal((rest) => ({ ...rest, order:order + 1 })); 
    } else if (value === "down" && order !== 0) {
      setVal((rest) => ({ ...rest, order: order - 1 })); 
    }
    setVal((rest) => ({ ...rest, alerts: Names[order] }));
  }


  return (
    <>
       
        <button
          onClick={slider}
          id="up"
        >
          up
        </button>

        <p>
          {getVal.alerts}
        </p>

        <button
          onClick={slider}
          id="down"
        >down
        </button>
</>
)
}