Preserving state across a "back"

I have a Javascript accordion.

The accordion starts in the completely closed state.

The accordion opens up to a bunch of links. If the user clicks on a
link it takes the user to a document that I have created and display.

What I want is for the user to be able to click on the back button and
have the accordion remember its state.

I'm not asking for Javacript help. I'm just wondering how in Rails I
detect that "I went to the document and that I am returning from the

There is no username so I guess the info needs to go in the session

Suggestions on how to preserve state across a "back' would be

I think the problem is that you do not send the request to the server
when you hit the back button.
That's why I can only imagine a js solution to your problem.
There are some good jquery and prototype plugins released that can be
Take a look @ reallysimplehistory or YUI library: browser history