title: Data binding in Windows Phone 8 app using ListBox
body: <p>Here is my code. What it doing. I have one textbox(button) with text Book name, when I click on it I can change text in textbox using binding. But now I add another textbox for author name and I dont know how bind it. If I use same method like for Book name its not works or text from book name is too in book author. All text are changed via popup setting page. </p>
  
  <p>My source here: <a href="https://dl.dropbox.com/u/40039421/App1.rar" rel="nofollow">https://dl.dropbox.com/u/40039421/App1.rar</a>.
  Image here:  <a href="https://dl.dropbox.com/u/40039421/helpp.png" rel="nofollow">https://dl.dropbox.com/u/40039421/helpp.png</a></p>
  
  <pre><code> public partial class MainPage : INotifyPropertyChanged
  {
      private ObservableCollection&lt;Book&gt; _books = new ObservableCollection&lt;Book&gt;();
      public ObservableCollection&lt;Book&gt; AllBooks
      {
          get { return _books; }
          set { _books = value; }
      }
  
      ...
  
      private void InitializeData()
      {
  
          var bookName1 = new Book { Id = 1, BookName = "Small red apple",AuthorName = "Daniel"};
          ...
  
          AllBooks.Add(bookName1);
         ...
  
          OnPropertyChanged("AllBooks");
      }
  
      public event PropertyChangedEventHandler PropertyChanged;
  
      public void OnPropertyChanged(string propertyName)
      {
          if (PropertyChanged != null)
          {
              PropertyChanged(null, new PropertyChangedEventArgs(propertyName));
          }
      }
  
      private void btnGreenBook_Click(object sender, RoutedEventArgs e)
      {
          var button = sender as Button;
          if (button != null)
          {
              Popup popup = new Popup();
              popup.VerticalOffset = 30;
              PopupSettingPage control = new PopupSettingPage();
              popup.Child = control;
              popup.IsOpen = true;
  
              control.btnSave.Click += (s, args) =&gt;
              {
                  var id = Convert.ToInt32(button.Tag);
                  var book = AllBooks.FirstOrDefault(sub =&gt; sub.Id == id);
                  if (book != null)
                  {
                      book.BookName = control.BookName;
                      book.OnPropertyChanged("BookName");
  
                  }
  
                  popup.IsOpen = false;
              };
  
             ...
  </code></pre>