Lag 
specifies a lag value to add to the list. Type in a positive integer or select one by clicking the spin box arrows. Duplicates
                        are allowed. 
                     
Add 
adds the value in the Lag spin box to the list of differencing lags. 
                     
Remove 
deletes a selected lag from the list of differencing lags. 
                     
OK 
closes the window and returns the specified list to the Factored ARIMA Model Specification window. 
                     
Cancel 
closes the window and discards any lags added to the list.