package net.saqoosha.thread {

    import org.libspark.betweenas3.tweens.ITween;
    import org.libspark.thread.IMonitor;
    import org.libspark.thread.Monitor;
    import org.libspark.thread.Thread;

    public class BetweenAS3Thread extends Thread {

        private var _tween:ITween;
        private var _monitor:IMonitor;

        public function BetweenAS3Thread(target:ITween) {
            _tween = target;
            _monitor = new Monitor();
        }

        public function cancel():void {
            interrupt();
        }

        override protected function run():void {
            _monitor.wait();
            interrupted(interruptedHandler);
            _tween.onComplete = _monitor.notifyAll;
            _tween.play();
        }

        private function interruptedHandler():void {
            if (_tween.isPlaying) {
                _tween.stop();
            }
        }
    }
}

Very simple.