konami.js

var logLevel = 0;

// a key map of allowed keys
var allowedKeys = {
	37: 'left',
	38: 'up',
	39: 'right',
	40: 'down',
	65: 'a',
	66: 'b'
};

// the 'official' Konami Code sequence
var konamiCode = ['up', 'up', 'down', 'down', 'left', 'right', 'left', 'right', 'b', 'a'];

// a variable to remember the 'position' the user has reached so far.
var konamiCodePosition = 0;

// add keydown event listener
document.addEventListener('keydown', function(e) {
	// get the value of the key code from the key map
	var key = allowedKeys[e.keyCode];
	// get the value of the required key from the konami code
	var requiredKey = konamiCode[konamiCodePosition];

	// compare the key with the required key
	if (key == requiredKey) {

	// move to the next key in the konami code sequence
	konamiCodePosition++;

	// if the last key is reached, activate cheats
	if (konamiCodePosition == konamiCode.length) {
		activateCheats();
		konamiCodePosition = 0;
	}
	} else {
		konamiCodePosition = 0;
	}
});

function activateCheats() {
	logLevel = 1;
	alert("debug activated");
}