Flash :: Send A Message To Stage If AS3 FLVPlayback Stream Isn't Found?

I've successfully created an FLVPlayback component using the component library and it's playing the streaming video that I want it to. My question is, if that stream is not online or cannot be found, how would I go about displaying a message on the stage to let the user know, there is no active stream.

UPDATED:
Here's my code -

thestream.addEventListener(NetStatusEvent.NET_STATUS, onNCStatus);
function onNCStatus(event:NetStatusEvent):void {
trace(event.info.code)[code].....

There's no output still. It seems like the function isn't getting invoked. However, if I place a trace outside the function (before it), I get a response: trace(NetStatusEvent.NET_STATUS);

the output:

netStatus