filozof-
During runtime, by default, LabVIEW has undo/redo data changes under the edit menu. This will undo/redo changes made to controls during runtime. If you want a more extensive undo/redo (custom for your application), you are going to have to do quite a few things
1) Create a custom runtime menu (Edit>>RunTime Menu) and place your own undo/redo controls on it
2) Keep an action history in your program
3) Catch the Shortcut menu event for your custom undo/redo controls
4) Reverse the last action in your histroy when you catch the event
This method would allow you undo entire operations (like resize, move, or whatever kind of functionality you are building into your application) unstead of just undoing data changes.
Xaq