How do many of the websites that have logins keep the username in the username field when the password is entered incorrectly. The form's action (it is on index.php) is another php file, which if the password is incorrect uses Header() to go back to the index and passes the error to it using GET. I could use GET to pass the username back to the form but this seems messy, and I have noticed that websites like SMF forums have the username stay in the username field without a messy URL.