Event.COMPLETE inside a function?

I have created a class named XMLclass and inside that class there is a function named returnFillColor.
The function looks like this:

public function returnFillColor(XMLchild:uint):String{
    var xmlLoader:URLLoader = new URLLoader();
    var xmlData:XML = new XML();
    xmlLoader.load(new URLRequest(xmlURL));
    xmlData = new XML(xmlLoader.data);
    XML.ignoreWhitespace = true
    return xmlData.Thing[XMLchild].color;

When i call this function from my main class, it returns nothing because the XML wasn’t done loading. I’ve double-checked this by adding addEventListener(Event.COMPLETE) outside the function.

So my question is!
Is there any way to return data from the xml-file with just one function?
(like adding event.Complete to the returnFillColor-function)

Really grateful for answer!