ActionScript 2.0 :: Getting Nested SWFs To Communicate?

Whats the simplest way to get a nested swf to modify the value of a variable located in the parent's swf? I'm not sure localConnection is what I need.

Here is a simplified example of my situation:

main.swf
content01.swf
content02.swf

main.swf loads and unloads content SWFs ontop of it's stage.

A piece of script in each content.swf needs to modify the _hieght of a movieclip in main.swf

(imagine the movieclip is a visual container for content, and content that takes up for space needs a taller content box; hence, changing the _height of the movieclip content box)

I'm also animating the movieclip's height expanding using actionscript:

ActionScript Code:
import mx.transitions.Tween;
import mx.transitions.easing.*;
var bodySize:Tween = new Tween(BOX_Body, "_height", Strong.easeOut, 200, 500, 2, true);

I figured I could put these lines of code on the first frame of the content.swfs, but change them to affect the "Box_Body" MC on the main.swf stage?