How can sessions be used in PHP to track whether a flash film has already been viewed on a website?

To track whether a flash film has already been viewed on a website, you can use sessions in PHP. When a user views the flash film, you can set a session variable to indicate that the film has been viewed. Then, on subsequent visits to the website, you can check this session variable to determine if the film has already been viewed.

session_start();

if (!isset($_SESSION['flash_film_viewed'])) {
    // Flash film has not been viewed yet
    $_SESSION['flash_film_viewed'] = true;
    // Add code here to display the flash film
} else {
    // Flash film has already been viewed
    // Add code here to display a message or alternative content
}