method CalcEdit.Undo ()
Call this function to undo the last edit-control operation.

TypeDescription
The control supports multi levels undo/redo support. The CTRL + Z reverses the last editing action, The CTRL + Y restores the previously undone action. Use the Undo method to undo the last edit-control operation. Use the CanUndo property to determine by code whether an undo operation is available. Use the CanRedo property  to determine by code whether a redo operation is available. Use the Redo method to redo the next action in the control's redo queue.