install error

[FlameProfi]

`function __autoload($class_name)
{
require_once $DOCUMENT_ROOT . “/classes/” . $class_name .“.php”;
}PHP Notice: Undefined variable: app in /var/www/bootstrap/app.php on line 26
PHP Fatal error: Uncaught Error: Call to a member function singleton() on null in /var/www/bootstrap/app.php:26
Stack trace:
#0 /var/www/artisan(20): require_once()
#1 {main}
thrown in /var/www/bootstrap/app.php on line 26

Notice: Undefined variable: app in /var/www/bootstrap/app.php on line 26

Fatal error: Uncaught Error: Call to a member function singleton() on null in /var/www/bootstrap/app.php:26
Stack trace:
#0 /var/www/artisan(20): require_once()
#1 {main}
thrown in /var/www/bootstrap/app.php on line 26
`