Event Listener for MC that dont exist

Hi all,

Quick question:

I am loading an external swf file. This file contains buttons, text fields etc

I am controlling it through a class file.

The problem I am having is setting up event listeners for objects that are not yet loaded on the external swf’s timeline yet…

Example

at the end of the swf i have a next button which is used to load the next swf file.
But this next btn only shows up on the file frame, so in the class file if I try to reference it, flash obviously thinks it doesnt exist…

Whats the best approach? I was thinking about using an on enter frame listener to detect when this button is loaded??