Flash - How To Sequence Events In AS3

I've been working with AS3. The crux of the problem is that before I run a function I need to know that certain conditions have been met, for example loading my config.xml and putting it into a class variable. Where I run into trouble is that URLLoader is async so I can't put code after the load, the only thing I can do is put it in a lambda on the listener.

var conf:Object = new Object();
var ldr:URLLoader = new URLLoader();
ldr.addEventListener(Event.COMPLETE, geoLoader, false, 0, true);
ldr.load(new URLRequest("[URL]"));
function geoLoader (e:Event):void {
[Code] .....

This worked great for short bits of code, but I've got a bunch of functions that are relying on huge amounts of preconditions (this pollutes the namespace if I use the first method) or functions that rely on one bit of the stack (which means that I can't use the second method even though it's slightly more obvious to me). So, my question is: How do flash professionals handle preconditions? I'm trying to find a solution that allows tons of preconditions as well as a solution that allows different orders of preconditions or just a few preconditions from a group.