Undo changes
You can undo changes that have not yet been saved to the list. When
		in edit mode, you can undo changes made to the current cell. 
			- Click 
		  Undo on the task pane toolbar, or press CTRL+Z.
  Notes  
			- For cells that support rich HTML formatting, each formatting command is
		  considered an edit.
- The Undo command is different from canceling edit mode by pressing Esc.
- You can't undo changes to the list after you add or remove an
		  attachment from a record. You can't undo changes to a row after the row has been saved.