Using swatch to make a checker board iamge in Illustrator

If you want to make a checker board in two colors easily, swatch may be useful.

This is a way of making it with Illustrator(I'm using CS2).
1.make four squares, paint them by two colors, and align them into a large square.
2.Select four squares and drag them into swatch board (this is the basic unit for a lattice).
3.make a large rectangle(or square).
4.paint it with lattice swatch.

that's it!