51help TIY
码：
<html> <head> <script type="text/javascript"> function isEventCancelable(event) { alert(event.cancelable); } </script> </head> <body onmousedown="isEventCancelable(event)"> <p>Click somewhere in the document. An alert box will tell if the event is a cancelable event.</p> </body> </html>
查看结果: