51help TIY
码：
<html> <head> <script type="text/javascript"> function isKeyPressed(event) { if (event.altKey==1) { alert("The ALT key was pressed!") } else { alert("The ALT key was NOT pressed!") } } </script> </head> <body onmousedown="isKeyPressed(event)"> <p>Click somewhere in the document. An alert box will tell you if you pressed the ALT key or not.</p> </body> </html>
查看结果: