ActionScript 3.0 :: Call On A Specific Child In A Container?

I am loaded images into a container that is being displayed on a map.  I've created a string of my images names and am looping a loader to load each image and add them to the container.
 
var overlays=["compsmall.png","compsmall3.png","compsmall3.png","compsmall4.png"]
var overlay_container:MovieClip= new MovieClip();
function calloverlays():void

[Code]....
 
Once all of my images are loaded into the container overaly_container how can I call on a specific child of the container?  For example how can I call on compsmall2.png once its been loaded into overlay_container?
 
I place these images onto a map by placing the whole container at the correct location.  I then turn layers on/off by adding and removing the children within the container.  This is why I'd like to specify a specific object in the parent.