how to save current game in chessboard.js

I am using chessboard.js script.

But I am facing a problem. I want to save a current game without end, save the current position and next time to use saved current position.

var cfg = { 
        position: 'r1bqkbnr/pppp1ppp/2n5/1B2p3/4P3/5N2/PPPP1PPP/RNBQK2R'
    };
var board = new ChessBoard('board', cfg);

Current position is showed correctly. But when I move, it goes to "start" state.

Solution

~~For storing in browser you could use cookies or localstorage.~~

~~Alternatively, you could send state to server and later read it using AJAX.~~

EDIT:

Looks like you have mistake in script. Instead of

new ChessBoard('board', cfg);

you should do

new ChessBoard('board', cfg.position);