I have a client requirement to manage data locally on an iPad with no network connection, any advice would be welcome please…

Constraints:
1) No network connection when the iPad is out on site.
2) Cannot install a native iOS app.

Preferred wrapper:
1) Locally installed HTML5 file.

Requirement:
1) The HTML5 page, presumably using JavaScript, must be able to save form data to the iPad on a button click event.
2) The User needs a facility to subsequently upload the data to a central web server, either with network connection or by cable.

What is the best way the achieve this ?

Thanks very much..