Install the database schema into your MySQL server from file 'schema_users.sql'
The first run leads to main page where you can either log in or register a new user
The task was to make special button that saves registration data in order to fill and register later. But instead I added automatic form ajax update that saves all the data right after any change done to text fields.
After logging in, the user sees the full information he entered when registering. He can easily update his registration data by clicking the dedicated button.