document.write('<div class="rss-box">');
document.write('<p class="rss-item"><em>Error:</em> Feed failed! Causes may be (1) No data  found for RSS feed https://mgr.edu.pl/category/firma/; (2) There are no items are available for this feed; (3) The RSS feed does not validate.<br /><br /> Please verify that the URL <a href="https://mgr.edu.pl/category/firma/">https://mgr.edu.pl/category/firma/</a> works first in your browser and that the feed passes a <a href="http://feedvalidator.org/check.cgi?url=https%3A%2F%2Fmgr.edu.pl%2Fcategory%2Ffirma%2F">validator test</a>.</p></div>');