Alternate Event Flow: username or email address is not registered in the system
1. The use case begins when the user loads the website
2. The user selects the forgot username/password option
3. The system brings up the forgot password screen
4. The user enters their email address OR username
5. The system verifies the email address OR username belongs to a valid user
6. The system redisplays the login screen with the message "Invalid username or email address