function isUserLoggedIn()
 {
     if (isset($_SESSION['username'])) {
         return true;
     } else {
         if (isset($_COOKIE['username']) || isset($_COOKIE['password'])) {
             $cookieUsername = $_COOKIE['username'];
             $cookiePassword = $_COOKIE['password'];
             $profile = new profile();
             if ($profile->isLoginDetailsAreValid($_COOKIE['username'], $_COOKIE['password'])) {
                 $_SESSION['username'] = $_COOKIE['username'];
                 return true;
             } else {
                 return false;
             }
         } else {
             return false;
         }
     }
 }