Unable to get the CRUD operation from the tutorial

I am having problems with in the CRUD operation from the tutorial I found here ...

http://www.c-sharpcorner.com/UploadFile/9f4ff8/wpf-perform-all-database-operations/

When I use any of the functions and re-run the applications the data is not showing the reflection in either SQL Server or at the front end. I am using to use this at work, which they have VS 2010 Ultimate Edition and SQL Enterprise Edition 2012.
Could it be something I need to do in the following and so what needs to be done? Could it be something I need to do in the following and so what needs to be done?

  SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\MyDatabase.mdf;Integrated Security=True;User 
   Instance=True");
  public MainWindow()
  SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\MyDatabase.mdf;Integrated Security=True; 
  User Instance=True");
  public MainWindow()