显示一个确认框，提醒访客点击什么

<p>点击按钮，显示确认框。</p>

<button onclick="myFunction()">点我</button>

<p id="demo"></p>

<script>

  function myFunction() {

    var x;

    var r = confirm("按下按钮!");

    if (r == true) {

      x = "你按下了\"确定\"按钮!";

    } else {

      x = "你按下了\"取消\"按钮!";

    }

    document.getElementById("demo").innerHTML = x;

  }

</script>