Looking for guidelines to create application file. For example I have an application that store user input into a file (Textbox, DataGrid, ListBox etc). I'm looking for WPF-C# implementation. I would like to have the following: If user edit a any form(Textbox, etc) an asterisk is displayed to the window title. When window is closed and asterisk is still there, a promote "Would you like to save changes" appears. If then saved the asterisk disappear. What do real applications use to create their application file? (Note: I'm not looking for database saving or SQL) I'm just looking for hints and guidelines. Thank you.