Another javascript library to handle keyboard combos is Mousetrap. Compared to the latter I like the way Keypress handle multiple combos declaration, but overall mousetrap seems more robust.

Also it's not clear to me how Keypress differentiate (if it does so) among a sequence of keys or a combinations. Mousetrap is using the + notation to handle that so you can declare different bindings for combinations 'command+shift+k' and sequences 'command shift k'.

https://github.com/ccampbell/mousetrap

There seems to be a new one of these each week. Here's my attempt from around a year ago: http://keithcirkel.co.uk/jwerty/

Great work just wanted to say that Print screen button was not working for me. Running Chrome 22.0.1229.79 on Windows 7.