private void CreateNotebook(object arg)
        {
            MainWindowInstance.ShowInputAsync("Add notebook", "Name:").ContinueWith(delegate(Task <string> task)
            {
                string newName = task.Result;
                if (string.IsNullOrEmpty(newName))
                {
                    return;
                }

                Notebook nb = new Notebook
                {
                    Name    = newName,
                    Created = DateTime.Now
                };
                nb.Save();

                var newNotebook = ViewModelLocator.Instance.GetNotebookViewModel(nb);

                List <NotebookViewModel> temp = new List <NotebookViewModel>();
                temp.AddRange(Notebooks.ToArray());
                temp.Add(newNotebook);
                temp.Sort((x, y) => string.Compare(x.Name, y.Name, StringComparison.Ordinal));

                Notebooks.Clear();
                temp.ForEach(Notebooks.Add);

                SelectedNotebook            = newNotebook;
                SelectedNotebook.IsSelected = true;
            });
        }