Undo data sheet edits

Occasionally, cell values are accidentally deleted or rows/columns added in unintended places but PRIMER 7 (unlike PRIMER 6) is able easily to back-track on such changes. There is a repeated Edit>Undo operation for all row and column manipulations on the Edit menu (between the Cut and Sort items). The Undo extends to any typing directly into cells of the data sheet or to copying and pasting rows/columns into it, whether from the same sheet or externally, from the clipboard.