使用向上/向下按钮更新我的HTML5滑块

<input type="range" id="mySlider" min="0" max="100" value="50">

var slider = document.getElementById("mySlider");
var upButton = document.getElementById("upButton");
var downButton = document.getElementById("downButton");

upButton.addEventListener("click", function() {
  if (slider.value < slider.max) {
    slider.value = parseInt(slider.value) + 1;
  }
});

downButton.addEventListener("click", function() {
  if (slider.value > slider.min) {
    slider.value = parseInt(slider.value) - 1;
  }
});

<button id="upButton">向上</button>
<button id="downButton">向下</button>