TotalFrames from Child

I am loading an external swf as a child and I want to get its “totalFrames”, but I get the following error: “Property totalFrames not found on flash.display.Loader and there is no default value.”

Is there a way to get totalFrames from a child? Here is what I have:


var movieArea = new Loader();
addChild(movieArea);

movieArea.load(new URLRequest("slide1.swf"));
movieArea.x=5;
movieArea.y=5;

var framesTot = trace(movieArea.totalFrames);