rows element may be nested inside another
rows element. The children of these nested rows are counted as normal rows as if they were part of the parent. However, nesting
rows elements allows groups of rows to have a separate appearance such as a different border, or separate scrolling may be defined for these rows.
Non-row related elements placed inside a
rows element occupy the full width of the grid and are placed in their corresponding positions between the rows.
More information is available in the XUL tutorial.
grid for an example.
Inherited from XUL element