Se usi FLVplayback component:

codice:
import mx.video.*;
var listenerObject:Object = new Object();
listenerObject.complete = function(eventObject:Object):Void {
trace("flv terminato");
getURL("tuolink.htm","_blank");//o tua azione
};
my_FLVPlybk.addEventListener("complete", listenerObject);
my_FLVPlybk.contentPath = "video.flv";
Se usi la connessione NetStream:

codice:
var connection_nc:NetConnection = new NetConnection();
connection_nc.connect(null);
var stream_ns:NetStream = new NetStream(connection_nc);
my_video.attachVideo(stream_ns);
stream_ns.play("video.flv");
stream_ns.onStatus = function(infoObject:Object) {
if(object.code == "NetStream.Play.Stop") {
trace("flv terminato");
getURL("tuolink.htm","_blank");//o tua azione
}
};