def get_offer_poster_name(html_parser):
    """
    This method returns the poster's name (and surname if available).

    :param html_parser: a BeautifulSoup object
    :rtype: string
    :return: The poster's name
    """
    element = html_parser.find(class_="box-person-name") or html_parser.find(class_="seller-box__seller-name")
    if not element:
        return
    name = element.text.strip()
    return name