​x
 
<!DOCTYPE html>
<html>
<head>
<script>
function isKeyPressed(event) {
  var text = "切换键未被按下！";
  if (event.shiftKey == 1) {
    text = "切换键被按下了！";
  }
  document.getElementById("demo").innerHTML = text;
}
</script>
</head>
​
<body>
​
<img src ="/i/eg_planets.jpg" alt="Planets" 
onmousedown="isKeyPressed(event)" />
​
<p>点击上面的图片，会提示您是否按下了 shift 键。</p>
​
<p id="demo"></p>
​
</body>
</html>
​