The following sections store your comments on your computer, not on the internet. This has the advantage of privacy but further means that you must both always use the same machine if you wish to compare your results on one screen. The data currently persists for 60 days after the last time you changed it. The technique used is called a 'cookie' : please check that your browser is enabled to store and read 'cookies' from our site if you cannot see your comments. This can usually be done from tools/options/privacy on your browser's menu bar, though in general cookies are enabled by default.