I have an event listener in Javascript, I can tell whether a key event is Ctrl (e.keyCode == 17), but how can I know this Ctrl comes from the right one or left
(e.keyCode == 17)
I don't think the keyCode is different.
You can use e.ctrlKey for a better way to determine if the control key was pressed.
e.ctrlKey
It seems Flash can not tell which one is pressed either (either that or coded incorrectly).