Adding and Removing Rows Using Arrows
In some editable grids, a new row can be added to another editable
grid (the grid on the left) by clicking the Add item button, , of the desired row in the grid
on the right:
When the Remove item button is clicked, , the row is transferred from the
grid on the right to the grid on the left. This change will not be
committed to the database until you save the object being maintained