user account system for existing PHP code

Project Description:
Hi all,

We have a some relatively simple order fulfillment software that currently relies on people using a link with a generated "key" in the URL to go view their orders. Orders are currently keyed to email address and unique generated hash.

We'd like to make it so that people can log in, using their email address and an automatically generated password when their order is placed

This project requires:

* a User class of some kind, session variables, etc. (any library you like, just keep the code neat and clean.)

* 3 pages of HTML (login form, account display with links to their files, "you have logged out" page)

* editing the order-placement code, giving customers an account if they don't have one already, and if they DO have an account, making sure their new order gets associated with their existing account.

* generating a good, secure password (mixture of alphanumerics 8 chars long will be fine) for the new account, and emailing this information to the user after EVERY PURCHASE (not just after the creation of the account).

That's it! Pretty straightforward.

On this project you will probably spend most of your time learning how our code is put together so that you can do the modifications correctly. The original programmer, unfortunately, cannot be contacted.

Thanks for your bids!