[flexcoders] Attaching custom data to events (while avoiding race condition)

[robbarreca]

Say I have two functions load() and handleComplete(event:Event). Right
now to get custom data to handleComplete I do something like this

private var someFlag:uint = 0;

function load() {
  loader.addEventListener(handleComplete);  
  someFlag = determineFlag();
  loader.loadSomeStuff();
}

function handleComplete(event:Event) {
  trace(someFlag);
}

But if I call this super fast, someFlag is gonna be wrong. I've seen a
method where you can add an anonymous function somehow, but I'm pretty
sure that even faced the same race condition problem. What is the
*proper* way to go about this?