Orthogonal Latin Squares

The applet below is just a tool for constructing orthogonal latin squares. Even for small sizes the task is not quite that trivial, unless one applies some simple theory.

In the applet, you can swap the letters in two not necessarily adjacent squares by clicking on those squares in succession. The squares must be located in the same column or the same row. You can also rotate the letters vertically and horizontally by clicking just outside the big square. Left and right letters in pairs are dealt with separately.