Как создать своего слушателя - вернее своё событие

[terbooter]

o = [];
o.a = 5;
o.watch("a", func);
broadcast = [];
AsBroadcaster.initialize(broadcast);
l1 = [];
l2 = [];
l3 = [];
broadcast.addListener(l1);
broadcast.addListener(l2);
broadcast.addListener(l3);
function func()
{
	broadcast.broadcastMessage("onEvent");
}
l1.onEvent = function()
{
	trace("l1");
};
l2.onEvent = function()
{
	trace("l2");
};
o.a = 10;