ActionScript 3.0 :: Loading Assets And Storing In Corresponding Arrays

Currently working on a project where I have to load in a ton of images and store them in corresponding arrays. The images are listed in seperate xml files bus.xml, car.xml, train.xml. The structure of the 3 files is the same e.g.
<images>
<image>car01.gif</image>
<image>car02.gif</image>
<image>car03.gif</image>
</images>

Now inside of the main class I have arrays for the images.
var busArray:Array;
var carArray:Array;
var trainArray:Array;

How would I create a function to recursively read each XML file and load the images into the array. I only want to create one Loader class. The bit that confuses me is how do I do the loop to load each file and once its loaded one file move onto the next until all the files from that XML file are loaded.

I thought it might be something like this,
var loader:Loader = new Loader();
loader.contentLoaderInfo.addEventListener(Event.CO MPLETE, imageLoaded);
for(i = 0; i < xmlFileLength; i++) {
loader.load(new URLRequest("car01.gif"));
} private function imageLoaded(e:Event) {
//add image to its array
//move onto next image
}

What I am thinking I need is a Flag of some sort to say the previous image is loaded. Move onto the next, but not sure how to structure it.