code: public function innerXML()
      {
          $xml = $this->outerXML();
          $pos = 1 + strpos($xml, '>');
          $len = strrpos($xml, '<') - $pos;
          return substr($xml, $pos, $len);
      }
docs: Return the XML content of current node as a string
  
  @return    string            Content of current node