7. Add session support so users can only see the loginHistory.php page if they have filled out the login form with valid data and have not clicked the logout link. You do not need to add any PHP validation to complete this step. Specifically: 1. In login.php: add PHP code so that if we arrived by POST, we start a session and store the username in it, then redirect to loginHistory.php 2. In loginHistory.php: add PHP code that starts a session and redirects back to login.php if $_SESSION["username"] has length of 0 3. Create a logout.php page with PHP code that starts a session, unsets and destroys it, then redirects back to login.php.