Shopkeeper and login system

I have a small webshop in Shopkeeper.
It simply uses eForm and Ideal payment.

I need a function the visitor is able to remember his info.
So when a visitor does a new order it doesn't needs to add address / zipcode etc etc again.
Maybe someone can help me out how to do this best way?

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I think the best way is:

- on the order page you can choose:

1) checkout as guest,
2) register or
3) login.


1) just the way it is at the moment, shows the orderform and choose the payment. (saves nothing)
2) just the way it is at the moment, just adds a password field, saves the emailadress with password to the webuser system so you can login the next time. Sends loginname and password by email.
3) a loginform, type e-mailaddress and password and redirects to the page with orderform and the fields are automaticly filled.