Hi. I would like help on undoing and redoing using the memento design pattern. I want to save a state that a board is in. Like a chessboard. If the user uses the undo option a previous board should be loaded and all of the states that the pieces was in. And the redo option should redo a previous move. I'm in quite a hurry to finish this project. This is about all I still have to do. Any help or suggestions on how to do it would be appreciated.