meta example with key codes

gistfile1.js

var KeyMap = {
	"Enter":13,
	"Shift":16,
	"Tab":9,
	"LeftArrow":37
};

for (var key in KeyMap) {
	KeyMap["is" + key] = function(compare,ev) {
		return ev.keyCode == compare
	}.bind(KeyMap,KeyMap[key]);
}

window.onkeyup = function(e) {
	if(KeyMap.isEnter(e)) {
		alert('its enter!');
	} else {
		alert(e.keyCode);
	}
}