How to close NetStream in class script

Question

How to close NetStream in class script
I use NetStream action to play the video. It’s working perfectly. Want to know how I can close my NetStream video to clicking on the button as in class scrip. I tray this
ns.close();
but got error
NetStream class action
package {
    import flash.display.SimpleButton;
    import flash.events.MouseEvent;
    import flash.media.Video;
    import flash.net.NetConnection;
    import flash.net.NetStream;
    import flash.media.SoundTransform;
    import flash.display.MovieClip;
    public class clickbutton extends SimpleButton {
          var ns:NetStream;
          var previousVolume:Number = 1;
          public function clickbutton() {
                this.addEventListener(MouseEvent.CLICK, clickF);
          private function clickF(e:MouseEvent):void{
               MovieClip(this.root).gotoAndStop(2, "Scene 1");
               var nc:NetConnection=new NetConnection();
               nc.connect(null);
               ns=new NetStream(nc);
               var video:Video=new Video(320, 200);
               video.x=(stage.stageWidth-320)/2;
               video.y=(stage.stageHeight-200)/2;
               ns.client=this;
               this.parent.addChild(video);
               video.attachNetStream(ns);
               ns.play("video_test.flv");
               controlsF();
               this.removeEventListener(MouseEvent.CLICK, clickF);
               this.parent.removeChild(this);
      private function controlsF():void{
          MovieClip(root).play_btn.addEventListener(MouseEvent.CLICK,playF);
          MovieClip(root).pause_btn.addEventListener(MouseEvent.CLICK,pauseF);
          MovieClip(root).muteToggle_btn.addEventListener(MouseEvent.CLICK,muteF);
          // add volume listener here.  you'll need to decide how you want to control volume.
                                                function playF(e:MouseEvent):void{
                                                                ns.resume();
                                                function pauseF(e:MouseEvent):void{
                                                                ns.pause();
                                                function muteF(e:MouseEvent):void{
                                                                if(ns.soundTransform.volume>0){
                                                                var st:SoundTransform=ns.soundTransform;
                                                                previousVolume=st.volume;
                                                                st.volume=0;
                                                                ns.soundTransform=st;
                                                } else {
                                                                st=ns.soundTransform;
                                                                st.volume=previousVolume;
                                                                ns.soundTransform=st;
                                public function onMetaData(eobj:Object): void {
                                                // this needs to be in the scope of your loader
                                public function onPlayStatus(eObj: Object): void {
                                public function onXMPData(eobj:Object):void{

Answer 1

I make to keyfram in my time line.
In 1st keyfram on the video button I use this code
package {
     import flash.display.SimpleButton;
     import flash.events.MouseEvent;
     import flash.media.Video;
     import flash.net.NetConnection;
     import flash.net.NetStream;
     import flash.media.SoundTransform;
     import flash.display.MovieClip;
          public class palyvideo extends SimpleButton {
               var ns:NetStream;
               var previousVolume:Number = 1;
                    public function palyvideo() {
                         this.addEventListener(MouseEvent.CLICK, clickF);
                    private function clickF(e:MouseEvent):void{
                         MovieClip(this.root).gotoAndStop(2, "Scene 1");
                         var nc:NetConnection=new NetConnection();
                         nc.connect(null);
                         ns=new NetStream(nc);
                         var video:Video=new Video(320, 200);
                         video.x=(stage.stageWidth-320)/2;
                         video.y=(stage.stageHeight-200)/2;
                         ns.client=this;
                         this.parent.addChild(video);
                         video.attachNetStream(ns);
                         ns.play("video_test.flv");
                         controlsF();
                         this.removeEventListener(MouseEvent.CLICK, clickF);
                         this.parent.removeChild(this);
               private function controlsF():void{
                    MovieClip(root).play_btn.addEventListener(MouseEvent.CLICK,playF);
                    MovieClip(root).pause_btn.addEventListener(MouseEvent.CLICK,pauseF);
                    MovieClip(root).muteToggle_btn.addEventListener(MouseEvent.CLICK,muteF);
                    // add volume listener here.  you'll need to decide how you want to control volume.
               function playF(e:MouseEvent):void{
                    ns.resume();
               function pauseF(e:MouseEvent):void{
                    ns.pause();
               function muteF(e:MouseEvent):void{
                    if(ns.soundTransform.volume>0){
                    var st:SoundTransform=ns.soundTransform;
                    previousVolume=st.volume;
                    st.volume=0;
                    ns.soundTransform=st;
               } else {
                    st=ns.soundTransform;
                    st.volume=previousVolume;
                    ns.soundTransform=st;
          public function onMetaData(eobj:Object): void {
               // this needs to be in the scope of your loader
          public function onPlayStatus(eObj: Object): void {
          public function onXMPData(eobj:Object):void{
In 2nd keyfram I use this code on reply button
package  {
     import flash.display.SimpleButton;
     import flash.display.MovieClip;
     import flash.events.MouseEvent;
     import flash.media.SoundMixer;
     import flash.media.Video;
     import flash.net.NetConnection;
     import flash.net.NetStream;
          public class reply extends SimpleButton {
                              public function reply() {
                                        this.addEventListener(MouseEvent.CLICK,clickFF);
                              private function clickFF(e:MouseEvent):void{
                                        SoundMixer.stopAll();
                                        MovieClip(this.root).gotoAndStop(1, "Scene 1");
                                        ns.close();
                                        //video.attachNetStream(null);
But when I click on reply button I got this compiler error