It took me some time, but I managed to get the DHTML Chess Widget working. Below you can find 1001 Brilliant Checkmates as a kind of exercise. You can make the moves by dragging and dropping a piece.
As soon as you have solved a problem the next problem will be loaded.
The widget works in Internet Explorer, Firefox and Chrome, but unfortunately originally not in Opera and Safari. It seems to work in the most recent versions. See the comments.