How to implement 'undo' operation in .net windows application?

Question

Assume that, a win form has certain input fields and user enters/re-enters some data.

How to retain data previously entered by \'undo\' operation?

Just I wan

Answer 1

http://blogs.msdn.com/kirillosenkov/archive/2009/06/29/new-codeplex-project-a-simple-undo-redo-framework.aspx