For users of Xojo, implementing a reliable Undo feature has never been a simple task, but with the introduction of TheBigUndo module by piDog Software, Undo's are almost an afterthought. heBigUndo can be as easy to use as copying the Module to your project and adding one line of code to your App's Open event. TheBigUndo includes the CustomUndo Interface and many methods and properties to give you total control of Undo's or just a little fine tuning. Try creating a Listbox with Rowtags or Celltags. Make the tags a Dictionary of Arrays of Pictures. See what comes out when you view it using window.XML. And TheBigUndo gives you fully cross-platform compatibility to boot. TheBigUndo not only adds Undo and Redo functions to your project, it provides access to an XML version of any window's state. Save it as a document and Load it back in. TheBigUndo can even set a window's StateChanged flag when the document is modified. Set the SavedState and TheBigUndo knows the difference between a changed window and a window that has been changed and changed back.