Saving, undoing and discarding changes

The UNDO button is enabled when there is at least one unsaved change to the grid.

• Clicking UNDO reverts the last change.  
• Repeatedly clicking undo reverts each change in sequence until there are no changes left to undo.

The REDO button is enabled when there is at least one undone change.

• Clicking REDO reapplies the change.

The RESET button is enabled when there is at least one unsaved change to the grid. 

• Clicking RESET reverts all changes since the grid was last saved.

Once the grid is in edit mode, the user must click either SAVE or CANCEL to return to the normal grid. 

SAVE applies all changes. CANCEL discards all unsaved changes. 

Note: CANCEL discards all unsaved changes and exits edit mode. RESET discards all unsaved changes but the grid remains in edit mode.