It there a tutorial for `js_of_ocaml` with simple graphics?

I have a simple application that uses the Graphics module to show some results (and that will be extended with simple interactions), and I would like to make it available as a web page. It seems that js_of_ocaml is the tool to use for that, but I could not find a tutorial showing how to do it. Is there one available that covers the ml part, the js part, and the html part?