try {

        require_once('db.php');

        $sql1 = "SELECT username FROM administrators WHERE username = '.$username.' ";
        $cmd = $conn->prepare($sql1);
        $cmd->execute();
        $admin = $cmd->fetchAll();
        //if the username is greater than 0 in the database say that username already exists

        if (empty($admin_id) == true){
            //set up the sql command
            $sql = "INSERT INTO administrators (username, password) VALUES (:username, :password)";
        }else{
            $sql ="UPDATE administrators SET username = :username, password = :password WHERE admin_id = :admin_id";
        }



        //5. hash the password for added security
        $hashed_password = hash('sha512', $password);

        //6. execute the save
        $cmd = $conn->prepare($sql);

        $cmd->bindParam(':username', $username, PDO::PARAM_STR, 50);
        $cmd->bindParam(':password', $hashed_password, PDO::PARAM_STR, 128);