Get a value out of a functioin

1

I’m trying to load xml data and then calculate the length of a xml node and then pass that value so that it’s available outside the function.
I’m obviously doing it wrong

also I don’t understand how tlbXML is being passed to the assign() function. does this happen automatically?

package  {
    
    import flash.display.MovieClip;
    import flash.display.Loader;
    import flash.events.*;
    import flash.net.URLLoader;
    import flash.net.URLRequest;
    import flash.xml.*;
    
    public class Test extends MovieClip {

        public function Test() {

        var tlbXML:XML;
        var tlbLoader:URLLoader = new URLLoader();
        tlbLoader.load(new URLRequest("tlbContent.xml"));
        tlbLoader.addEventListener(Event.COMPLETE, processTlbXML);
        function processTlbXML(e:Event):void {
        tlbXML = new XML(e.target.data);
        assign();
        }
        
        var tlbNode3Length:int = 0;

        function assign(){
        var tlbNode3:String = tlbXML.tlb.node3.toString();
        tlbNode3Length = tlbNode3.length;
        getValue(tlbNode3Length)
        }
    
        
        function getValue(tlbNode3Length){
        //this trace obvoiusly works
        trace(tlbNode3Length + " = tlbNode3Length inside function ");
        return tlbNode3Length;
        }
            
        //trying to pass the value of tlbNode3Length to var valueIGet
        var valueIGet:int = getValue(tlbNode3Length);
        
        trace(valueIGet + " = tlbNode3Length outside function "); 
            
        }    

    }
    
}

help is much appreciated thanks in advance.