Autocomplete filling out Email/Website/Address in Forms in Flash?

How do websites I've never been to fill out my information (email address, name, phone, etc.)? Sometimes they pick my old email instead of my new one, so they must be reading it from something I might be able to access with some javascript. I would like to be able to do something like this in Flash, so any ideas how I could tap into how it works with some javascript?

Update:

Having a little better understanding of what's going on, since the browser is suggesting the autocomplete values, is it possible to, in the Flash HTML 开发者_开发知识库template/wrapper, create forms with the same fields as your flash project, and when the user focuses in on a flash form item, it quickly shifts focus to the equivalent "hidden" html form item, gets the autocomplete value, and sends it back to flash? Is that possible?

Thanks!

Its not the site - its your browser. Generally, browsers look at the name of the form field you're in, and show data they've seen entered in that field before.

It would be a huge security hole if a site were able to look at things you've entered in other sites!