Working with Nested Movie Clips
Movie Clips can be controlled with Action Script. You must reference the movie clip by the instance name, then the property/method you want to view.
ufocontrol.gotoAndPlay(70);
Additionally, you can control nested movie clips. You need to reference the outer movie clip (by instance name), dot (.), then the internal movie clip (by instance name)
backgrd.graph.gotoAndStop(20);
The total code, including the event handler (the function), would look like:
function cloakHandler(event:MouseEvent):void {
ufocontrol.gotoAndPlay(70);
backgrd.graph.gotoAndStop(20);
}