function create_container($container_name=NULL)
    {
        if ($container_name != "0" and !isset($container_name))
            throw new SyntaxException("Container name not set.");
        
        if (!isset($container_name) or $container_name == "") 
            throw new SyntaxException("Container name not set.");

        if (strpos($container_name, "/") !== False) {
            $r = "Container name '".$container_name;
            $r .= "' cannot contain a '/' character.";
            throw new SyntaxException($r);
        }
        if (strlen($container_name) > MAX_CONTAINER_NAME_LEN) {
            throw new SyntaxException(sprintf(
                "Container name exeeds %d bytes.",
                MAX_CONTAINER_NAME_LEN));
        }

        $return_code = $this->cfs_http->create_container($container_name);
        if (!$return_code) {
            throw new InvalidResponseException("Invalid response ("
                . $return_code. "): " . $this->cfs_http->get_error());
        }
        #if ($status == 401 && $this->_re_auth()) {
        #    return $this->create_container($container_name);
        #}
        if ($return_code != 201 && $return_code != 202) {
            throw new InvalidResponseException(
                "Invalid response (".$return_code."): "
                    . $this->cfs_http->get_error());
        }
        return new CF_Container($this->cfs_auth, $this->cfs_http, $container_name);
    }