problem: event.altKey is undefined. environment: Linux/ FF 3.0.1 / jQuery-1.2.6
remark: when I am using older version (1.1.4) everything works fine. The following markup along with firebug will be handy to capture it. <html> <head> <script src="http://jqueryjs.googlecode.com/files/ jquery-1.2.6.js"></script> <script> $(document).ready(function (){ $.event.add(document, 'keydown', showEventDetails); }); function showEventDetails(event){ console.log("Alt:%s", event.altKey); } </script> </head> <body> </body> </html>