Please Help with Preloader

programming flash
1

I pulled this preloaded from http://help.adobe.com/en_US/AS2LCR/Flash_10.0/help.html?content=00000421.html.

For some reason it’s not working as I thought it would.
What’s happening is that while preloading, you can hear the sound but no video.

My video component is named, my_video.

var connection_nc:NetConnection = new NetConnection();
connection_nc.connect(null);
var stream_ns:NetStream = new NetStream(connection_nc);
my_video.attachVideo(stream_ns);
stream_ns.play("http://www.helpexamples.com/flash/video/lights_short.flv");

this.createTextField("loaded_txt", this.getNextHighestDepth(), 10, 10, 160, 22);
var loaded_interval:Number = setInterval(checkBytesLoaded, 500, stream_ns);
function checkBytesLoaded(my_ns:NetStream) {
    var pctLoaded:Number = Math.round(my_ns.bytesLoaded / my_ns.bytesTotal * 100);
    loaded_txt.text = Math.round(my_ns.bytesLoaded / 1000) + " of " + Math.round(my_ns.bytesTotal / 1000) + " KB loaded (" + pctLoaded + "%)";
    progressBar_mc.bar_mc._xscale = pctLoaded;
    if (pctLoaded >= 100) {
        clearInterval(loaded_interval);
    }
}

Please help

Thank you