Flash - Using NetConnection Class To Live Video Feed?

I'm trying to use the NetConnection class to connect to a live video feed on an external server. I have it set up to start playing my video when the user clicks a Play button, however, this appears in my output every time I click the Play button:

ArgumentError: Error #2126: NetConnection object must be connected.
at flash.net::NetStream/ctor()
at flash.net::NetStream()
at Over/connectLiveStream()[Over::frame2:31]

Here is the (I think relevant) code:
if (playVid.label == "Play") {
nc = new NetConnection();
nc.objectEncoding = flash.net.ObjectEncoding.AMF0;
nc.connect("rtmp://my.rtmp.server:1935/live/");
nsPlay = new NetStream(nc);
nsPlay.play("livestream.flv");
}