public function flatArray($array = array(), $skip = array())
    {
        if (count($array) == 0) {
            $this->errorMessage[] = 'FLAT_ARRAY: array for flatArray is empty';
            return array();
        }
        $return = array();
        foreach ($array as $name => $item) {
            if (!in_array($name, $skip)) {
                if (is_array($item)) {
                    foreach ($item as $subItem) {
                        $return[] = $subItem;
                    }
                } elseif (!is_array($item)) {
                    $return[] = $item;
                }
            }
        }
        return $return;
    }