$option=array();
		$option['driver']   = 'mysqli';            // Database driver name
		$option['host']     = 'dbserver';    // Database Host name
		$option['user']     = 'login';       // User for database authentication
		$option['password'] = 'password';   // Password for database authentication
		$option['database'] = 'db';      // Database name
		$option['prefix']   = '';             // Database prefix (may be empty)
		$db=JDatabaseDriver::getInstance($option);

		try {
			$db->transactionStart();
			$db->setUTF();

			$query=$db->getQuery(true);
			$query->select('*');
			$query->from($db->quoteName('status'));
			
			$db->setQuery($query);
			$result = $db->execute();
			if($result===false)
				$db->transactionRollback();
			else
			{
				$db->transactionCommit();
				$liste=$db->loadAssocList();
				...
			}
		}
		catch (Exception $e) {
			$db->transactionRollback();
		}