OOP Question: Calling Function in Root?

Question

This is kinda complicated, and I'm still trying to wrap my head around the whole concept of OOP. So right now I am building a XML Gallery, and in the FLA (Root) I've added the thumbnails. Everytime the thumbnails been clicked, it will bring up the "Detail" movieclip, which also is created in the root. And inside the Detail movieclip, I am creating a few buttons with an external class. My question is how can I call a function in the FLA (Root) when I click on the buttons inside the Detail movieclip? Note it seems I've successfully import my external class in both the root and the Detail movieclip.
I hope I'm making sense. >_<
Thanks for any help in advance.

Answer 1

use:
In the DetailButtons class:
_button.addEventListener(MouseEvent.CLICK, onClick, false, 0, true);
private function onClick(evt:MouseEvent):void {
     dispatchEvent(new Event("Clicked");
In the Main FLA / Root:
var detailButtons:DetailButtons = new DetailButtons();
addChild(detailButtons);
detailButtons.addEventListener("Clicked", goBack);
function goBack(evt:Event):void{
    trace("Go Back");