​x
 
<!DOCTYPE html>
<html>
<body>
​
<div onmousedown="WhichButton(event)">用您的鼠标按钮之一单击此文本可返回一个数字。
  <p>1 = 鼠标左键</p>
  <p>2 = 鼠标中键</p>
  <p>3 = 鼠标右键</p>
</div>
​
<p><b>注释：</b>IE8 及更早版本不支持 which 属性。</p>
​
<script>
function WhichButton(event) {
  alert("You pressed button: " + event.which)
}
</script>
​
</body>
</html>
​