Custom skin not working as desired

I wanted to change the default behavior of the Flash Video Player skin such that “caption” Button works as a link and opens a new browser window.

I took SkinOverAll.fla saved as SkinOverAllCustom.fla and added following code:

this.captionToggle_mc.addEventListener(MouseEvent. CLICK, onCaptionClick);
function onCaptionClick (e:MouseEvent):void
trace(“caption button clicked!”);
var url:String = “”;
var request:URLRequest = new URLRequest(url);
try {
navigateToURL(request, ‘_blank’); // second argument is target
} catch (e:Error) {
trace(“Error occurred!”);

When I test this clip as SkinOverAllCustom.swf , the caption button click opens a new browser with

But now when I add this skin in my FLVPlayback component it doesnt work, code is added as: = “SkinOverAllCustom.swf”;
player.skinBackgroundColor = 0x5E5E5E;
player.skinBackgroundAlpha = 0.85;
captioning.flvPlayback = player;

player being the instance of FLVPlayback and captioning being instance of FLVPlaybackCaptioning

Can anybody suggest what changes should I make so that caption button works as a button and I can control its onclick event?