AS error loading video MX04

hi, im jsut trying a tutorial on adding external video to an swf and i get the AS error:
Error Scene=Scene 1, layer=Layer 1, frame=1:Line 1: Statement must appear within on handler
vid_btn.onRelease = function() {

Total ActionScript Errors: 1 Reported Errors: 1

*********the AS code to load the video is: **************

vid_btn.onRelease = function() {
myVideo_nc = new NetConnection();
myVideo_nc.connect(null);
newStream_ns = new NetStream(myVideo_nc);
videoHolder.attachVideo(newStream_ns);
newStream_ns.play(“build150kb.flv”);
};

It must be simple but im new to AS , thanks