addEventListener in code

addEventListener.js

var listeners = {};
function addEventListener(event, callback, capture){
    if(!listeners[event]){
		listeners[event] = [];
	}
	listeners[event].push(callback);
}

function removeEventListener(event, callback, capture){
	if(listeners[event]){
		var handlers = listeners[event];
		for(var i=0, l=handlers.length; i<l; i++){
			if(handlers[i] === callback){
				handlers.splice(i, 1);
				break;
			}
		}
	}
}

Node.prototype.addEventListener = addEventListener;
Node.prototype.removeEventListener = removeEventListener;

on.js

function on(node, event, callback){
	var signal = {
		destroy: function(){
			node.removeEventListener(event, callback, false);
		}
	};
	node.addEventListener(event, callback, false);

	return signal;
}