Async Void method from JavaScript

default.js

        function dostuff() {
            var j = document.getElementById("mycontent");
            j.innerText = "";
            var b = new WindowsRuntimeComponent6.Class1();
            var c = b.initializeAsync().done(onStuffComplete, onStuffError);
        }

        function onStuffComplete() {
            var j = document.getElementById("mycontent");
            j.innerText = "the function completed";
        }

        function onStuffError() {
            var j = document.getElementById("mycontent");
            j.innerText = "the function had an error";
        }

someclass.cs

public IAsyncAction InitializeAsync()
        {
            return AsyncInfo.Run(async delegate
            {
                var storagefile = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(@"WindowsRuntimeComponent6\TextFile1.txt");
                using (var strm = await storagefile.OpenStreamForReadAsync())
                {
                    using (StreamReader rdr = new StreamReader(strm))
                    {
                        string data = rdr.ReadToEnd();
                    }
                }
            });
        }