14.1 Objectives

Write a script to do the following (as overall behavior, not script logic!):

• Prompt a user to log in. Provide a text field for username, and a password field for password.
• Use a checkbox so a user can indicate whether he/she wants to register. All users must be registered before they can log in. The caption of this checkbox should be something like ``Check this box for first time users.''
• Use a submit button to initiate the log in process.
• If the ``first time user'' checkbox is cleared:
  • Check the name and password against entries in the database
  • If the username is found
    • If the password matches
      • If NUMFAIL is at least five, print ``Call to revalidate the account'', then present the login form again
      • If NUMFAIL is less than five: Reset NUMFAIL to zero, as this is just the number of consecutive login failure. Present a document to indicate the user is logged in. This can be as simple as just a message saying ``You are now logged in.'' Do not present the login form again!
    • If the password does not match
      • increment the ``NUMFAIL'' field
      • Print ``Incorrect username or password''
      • Present the login form again
  • If the username is not found
    • Print a message at the beginning of the form, and ask for login again.
    • The message should not indicate that the username is not found. Just ``Incorrect username or password'' should be sufficient.
• If the ``first time user'' checkbox is checked:
  • Check to see if the username is already in the database
  • If the username is already in the database
    • Print a message like ``Username is already used.''
    • Present the login form again.
  • If the username is not in the database
    • Present a new user form.
    • Present the username (email address) in text, but not in a text field.
    • Present a text field for a nickname.
    • Use a submit button for submission.
    • When the user submits, add a new entry in the database.
    • Jump to the logged in screen saying ``You are now logged in.''