setInterval() problems

programming flash
1

I know it’s a rather stupid problem, but i can’t seem to get my function to work, i have the following code, just an abstract peace of code, works beautifully:

 
PlaatsDAO.getInstance().getItems(cb_plaatsenBezet, _global.ticketArr[0], this);

But i want this executed every 2 seconds, so i replaced it with:

checkSeats = function () {
PlaatsDAO.getInstance().getItems(cb_plaatsenBezet, _global.ticketArr[0], this);};
setInterval(checkSeats, 2000);

Now, this didn’t work, thinking that it was a scope problem, i replace my code with the following:

checkSeats = function () {
PlaatsDAO.getInstance().getItems(this._parent.cb_plaatsenBezet, _global.ticketArr[0], this._parent);
setInterval(checkSeats, 2000);

Anyone have an idea as to what i’m doing wrong? thx