​x
 
<!DOCTYPE html>
<html>
<body>
​
复选框：<input type="checkbox" id="myCheck" value="myvalue">
​
<p>单击下面的按钮可显示和/或更改上面复选框的 value 属性的值。</p>
​
<button onclick="display()">显示值</button>
<button onclick="change()">修改值</button>
​
<script>
function display() {
  var x = document.getElementById("myCheck").value;
  alert("复选框的值是：" + x);
}
​
function change() {
  var x = document.getElementById("myCheck").value = "newCheckboxValue";
  alert ("该值已更改为：" + x);
}
</script>
​
</body>
</html>
​