console 命令行工具 X clear

console

function isKeyPressed(event)
{
  if (event.shiftKey==1)
    {
    alert("The shift key was pressed!")
    }
  else
    {
    alert("The shift key was NOT pressed!")
    }
  }

<body onmousedown="isKeyPressed(event)"> 
 <p>在文档中点击某个位置。消息框会告诉你是否按下了 shift 键。</p>  
</body>