//public string status { get; set; }
        public void Execute(object parameter)
        {
            _canExecute = false;
              //  status = "sending";
            byte[] b;
            var dialog = new OpenFileDialog();

            dialog.Multiselect = false;

             var flvm = (FolderListVM)parameter;
            if (string.IsNullOrEmpty(flvm.SelectedFolder))
            {
                MessageBox.Show("Please select a folder.");
                return;
            }

            bool? fileselected = dialog.ShowDialog();
            if (fileselected.HasValue && fileselected.Value)
            {
                var fileinfo = dialog.File;
                using (FileStream reader = fileinfo.OpenRead())
                {
                    var fs = new FileServiceClient();
                    b = new byte[fileinfo.Length];
                    reader.Read(b, 0, (int)fileinfo.Length);

                    string fileName = fileinfo.Name;
                    fs.SendFileCompleted += (sender, args) =>
                    {
                        var res = (string) args.Result;
                        if (res != "success")
                        {
                            MessageBox.Show("Error uploading: " + res);
                        }
                        else
                        {
                            flvm.CommandListFiles.Execute(flvm);
                        }
                    };
                    try
                    {
                        string filepath = Path.Combine(flvm.ClientRepository, flvm.SelectedFolder) + "\\" + fileName;
                        fs.CheckFileExistsCompleted += (sender, args) =>
                        {
                            var Exists = (bool)args.Result;
                            if (!Exists)
                            {

                                fs.SendFileAsync(b, filepath);
                            }
                            else
                            {
                                var resu = MessageBox.Show("File already exists, would you like to replace?",
                                    "FileExists", MessageBoxButton.OKCancel);
                                if (resu == MessageBoxResult.OK)
                                {
                                    fs.SendFileAsync(b, filepath);
                                }
                            }
                        };
                        fs.CheckFileExistsAsync(filepath);

                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.Message);
                    }

                    //        status = filebytes;
                }
            }

            _canExecute = true;
        }