Publish live video & play

Question

Hi all, i use the code below to publish my cam, and i can play it in the same application. Then i copy and renamer it videoPlayer2.as then i use
displayPlaybackVideo(); method but it says "TypeError: Error #1009: Cannot access a property or method of a null object reference.". How can i get the published live video from another app.
Thanks..
videoPlayer.as // publish and play
package
     import flash.display.MovieClip;
     import flash.net.NetConnection;
     import flash.net.NetStream;
     import flash.media.Camera;
  import flash.media.Microphone;
     import flash.media.Video;
     import flash.events.NetStatusEvent;
  import fl.video.FLVPlayback;
     public class videoPlayer extends MovieClip
            var nc:NetConnection;
   var ns:NetStream;
   var nsPlayer:NetStream;
   var vid:Video;
   var vidPlayer:Video;
   var cam:Camera;
   var mic:Microphone;
           public function videoPlayer()
                nc=new NetConnection();
                nc.connect("rtmp://localhost/video");
                nc.addEventListener(NetStatusEvent.NET_STATUS,onNetStatus);    
           function onNetStatus(event:NetStatusEvent):void
      trace(event.info.code);
       if(event.info.code == "NetConnection.Connect.Success"){
           publishCamera();
           displayPublishingVideo();
           displayPlaybackVideo();
     function publishCamera() {
        cam = Camera.getCamera();
    cam.setMode(160,120,15);
    cam.setQuality(100000,0);
       mic = Microphone.getMicrophone();
       ns = new NetStream(nc);
       ns.attachCamera(cam);
       ns.attachAudio(mic);
       ns.publish("myCamera", "record");
  function displayPublishingVideo():void {
   vid = new Video(200,200);
   vid.x = 10;
      vid.y = 10;
      vid.attachCamera(cam);
      addChild(vid); 
  function displayPlaybackVideo():void{
      nsPlayer = new NetStream(nc);
      vidPlayer = new Video(200,200);
   nsPlayer.client=this
      nsPlayer.play("myCamera",-1,-1);
   vidPlayer.x = cam.width + 80;
      vidPlayer.y = 10;
      vidPlayer.attachNetStream(nsPlayer);
      addChild(vidPlayer);

Answer 1

if i publish camera in videoPlayer2, displayPlaybackVideo() method is working, but i cannot catch the video whichs is published from videuPlayer.as.
thanks
//videoPlayer.as
package
     import flash.display.MovieClip;
     import flash.net.NetConnection;
     import flash.net.NetStream;
     import flash.media.Camera;
  import flash.media.Microphone;
     import flash.media.Video;
     import flash.events.NetStatusEvent;
  import fl.video.FLVPlayback;
     public class videoPlayer extends MovieClip
            var nc:NetConnection;
            var ns:NetStream;
            var nsPlayer:NetStream;
            var vid:Video;
            var vidPlayer:Video;
            var cam:Camera;
            var mic:Microphone;
           public function videoPlayer()
                nc=new NetConnection();
                nc.connect("rtmp://localhost/video");
                nc.addEventListener(NetStatusEvent.NET_STATUS,onNetStatus);    
           function onNetStatus(event:NetStatusEvent):void
      trace(event.info.code);
       if(event.info.code == "NetConnection.Connect.Success"){
           publishCamera();
           displayPublishingVideo();
           displayPlaybackVideo();
     function publishCamera() {
        cam = Camera.getCamera();
    cam.setMode(160,120,15);
    cam.setQuality(100000,0);
       mic = Microphone.getMicrophone();
       ns = new NetStream(nc);
       ns.attachCamera(cam);
       ns.attachAudio(mic);
       ns.publish("myCamera", "append");
  function displayPublishingVideo():void {
   vid = new Video(200,200);
   vid.x = 10;
      vid.y = 10;
      vid.attachCamera(cam);
      addChild(vid); 
  function displayPlaybackVideo():void{
      nsPlayer = new NetStream(nc);
      vidPlayer = new Video(200,200);
   nsPlayer.client=this
      nsPlayer.play("myCamera",-1,-1);
   vidPlayer.x = cam.width + 80;
      vidPlayer.y = 10;
      vidPlayer.attachNetStream(nsPlayer);
      addChild(vidPlayer);
//videoPlayer2.as
package
     import flash.display.MovieClip;
     import flash.net.NetConnection;
     import flash.net.NetStream;
     import flash.media.Camera;
     import flash.media.Microphone;
     import flash.media.Video;
     import flash.events.NetStatusEvent;
     import fl.video.FLVPlayback;
     public class videoPlayer2 extends MovieClip
            var nc:NetConnection;
            var ns:NetStream;
            var nsPlayer:NetStream;
            var vid:Video;
            var vidPlayer:Video;
            var cam:Camera;
            var mic:Microphone;
           public function videoPlayer2()
                nc=new NetConnection();
                nc.connect("rtmp://localhost/video");
                nc.addEventListener(NetStatusEvent.NET_STATUS,onNetStatus);    
           function onNetStatus(event:NetStatusEvent):void
                trace(event.info.code);
                 if(event.info.code == "NetConnection.Connect.Success"){
                      displayPlaybackVideo();
       function displayPlaybackVideo():void{
                nsPlayer = new NetStream(nc);
                vidPlayer = new Video(200,200);
                nsPlayer.client=this
                nsPlayer.play("myCamera",-1,-1);
                 vidPlayer.x = cam.width + 80;
                 vidPlayer.y = 10;
                vidPlayer.attachNetStream(nsPlayer);
                addChild(vidPlayer);