getCharCode and non-character keys

String.fromCharCode works for converting the keycodes into the character on the keyboard that they represent, but it does not work with all the keys.

If the keys I am using are A,B,C,D,etc this function works, but if they are Keyboard.LEFT, Keyboard.ENTER, Keyboard.SHIFT, etc, fromCharCode doesnt return anything with these key codes.

This website:
http://www.signar.se/blog/as-3-charcodes/
apparently shows that these keys (like SHIFT, ENTER) have no char code, just a key code.

There must be some way to convert these non-character key codes into strings that say what the key was, right?