Progress Event & MC

I have a progress event looking at a Progress Bar inside of a MC. I reference the MC but nothing happens when the progress bar is complete… Code is Below.

addEventListener(ProgressEvent.PROGRESS, whenDone);

function whenDone(event:ProgressEvent):void {
if(test_mc.progressBar.width == 50){
work_txt.text = “work”;}}

	whenDone(null);