[jQuery] My code which use keydown(fn) don't work on IE?? help

[liec]

$(window).keydown(function(e){
       if (e.keyCode == 13)
               sendmsg();
});


$(window).keydown(function(ke){
        switch (ke.keyCode)
                {
                case 13:
                        alert('enter');
                        sendmsg();
                        break;
                }
});

They work well on firefox and chrome
but It is not work on IE7.0 ?