Flash CS3 Professional. The id parameter is new in CS4.
fl.removeEventListener(eventType, id)
eventType A string that specifies the event type to remove from this callback function. Acceptable values are "documentNew", "documentOpened", "documentClosed", "mouseMove", "documentChanged", "layerChanged", "timelineChanged", and "frameChanged".
id An integer that specifies the listener ID returned from the corresponding fl.addEventListener() call.
A Boolean value of true if the event listener was successfully removed; false if the function was never added to the list with the fl.addEventListener() method.
Unregisters a function that was registered using fl.addEventListener().
The following example removes the event listener associated with the documentClosed event:
fl.removeEventListener("documentClosed", eventID);