How do I use FlashVars with ActionScript 3.0?

package {
    import flash.display.Sprite;

    public class Main extends Sprite {

        public function Main() {
            var test1:String    = '';

            if (this.loaderInfo.parameters.test1 !== undefined) {
                test1 = this.loaderInfo.parameters.test1;
            }
        }
    }
}

var paramObj:Object = LoaderInfo(this.root.loaderInfo).parameters;