返回当前播放视频的总时间myns.totalTime无效果

private var myns:NetStream;
private var nc:NetConnection;
private var ns:NetStream;
public function setFlvWindow(ns:NetStream)
{
trace("ns=" + ns);
myns = ns;
}
nc = new NetConnection();
ns = new NetStream(nc);
setFlvWindow（ns）