Removing a listener

programming flash
1

I have this code on the first frame of a movieclip:

function onCreditChanged(eventObject:Object)
{
if (eventObject.newCredit >= 250) {
_root.footy.gotoAndStop(“2”);
}else{
_root.footy.gotoAndStop(“1”);
}
}
_root.addEventListener(“CREDIT_CHANGED”, onCreditChanged);

When going to frame 2 I want to stop the listener but can’t seem to manage it. It won’t ever stop!

How would I remove the event listener in this situation?

thanks