code: public static String getChildText(Element elem, String childTagName)
      {
          NodeList nodeList = elem.getElementsByTagName(childTagName);
          int len = nodeList.getLength();
          if (len == 0)
          {
              return null;
          }
  
          return getElementText((Element)nodeList.item(len - 1));
          
     }
docs: Return content of child element with given tag name.
  If more than one children with this name are present, the content of the last
  element is returned.
  
  @param elem
  @param childTagName
  @return content of child element or null if no child element with this name was found