If played once do not play again

I need to know how to make video play only once because code below is put on 102frame and when i go back i go to 50frame and video starts over again… I need video to play only once… no matter what…

here is the code i put for video…

var nc2:NetConnection = new NetConnection();
nc2.connect(null); 
var ns2:NetStream = new NetStream(nc2);
var vid:Video = new Video(220, 150);
this.addChild(vid);
vid.attachNetStream(ns2);
ns2.play("test.flv");
var netClient:Object = new Object();
netClient.onMetaData = function(meta:Object)
{        trace(meta.duration);};
 ns2.client = netClient;