Save history in iPhone webapp

I made an iPhone Webapp that allows an user to consult a distant database. At some point the user has to enter a code wich is quite long (about 17 digits). I would like to make the webapp remember the 3 or 5 last codes he type开发者_高级运维d.

How can I achieve this using the cache-manifest? (I have never used it but it looks like the right solution).

Thanks you for your attention.

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In the end, I figured out that using cookies would be the easiest way to do it, and hopefully cookies are actually kept for Webapps. I will struggle with the cache-manifest on an other episode.