Why cant I call this prototype?

1

I have a prototype function I found online, but I cant figure out how to call it. I am trying to disable components of my flv player


mx.video.FLVPlayback.prototype.enableButtons = function(bEnabled:Boolean) {
    trace("DF");
    this.skin_mc.seekBar_mc.handle_mc._visible = bEnabled;
    this.skin_mc.seekBar_mc.volumeBarHandle_mc._visible = bEnabled;
    if (bEnabled) {
        this.playButton = this.skin_mc.layout_mc.play_mc;
        this.stopButton = this.skin_mc.layout_mc.stop_mc;
        this.backButton = this.skin_mc.layout_mc.back_mc;
        this.forwardButton = this.skin_mc.layout_mc.forward_mc;
        this.seekBar = this.skin_mc.seekBar_mc;
        this.muteButton = this.skin_mc.layout_mc.volumeMute_mc;
    } else {
        this.onEnterFrame = function() {
            this.playButton = this.skin_mc.layout_mc.play_mc.disabled_mc;
            this.stopButton = this.skin_mc.layout_mc.stop_mc.disabled_mc;
            this.backButton = this.skin_mc.layout_mc.back_mc.disabled_mc;
            this.forwardButton = this.skin_mc.layout_mc.forward_mc.disabled_mc;
            this.muteButton = this.skin_mc.layout_mc.volumeMute_mc.disabled_mc;
            this.seekBar = null;
            this.volumeBar = null;
            updateAfterEvent();
            delete this.onEnterFrame;
        };
    }
};

I cant even get it to trace out…ive tried

enableButtons(false);
vidPlayer.enableButtons(false);

no luck…any idea?