Implement interface Element #23

interface Element : Node {
  readonly attribute  DOMString            tagName;
  DOMString                 getAttribute(in DOMString name);
  void                      setAttribute(in DOMString name, 
                                         in DOMString value)
                                         raises(DOMException);
  void                      removeAttribute(in DOMString name)
                                            raises(DOMException);
  Attr                      getAttributeNode(in DOMString name);
  Attr                      setAttributeNode(in Attr newAttr)
                                             raises(DOMException);
  Attr                      removeAttributeNode(in Attr oldAttr)
                                                raises(DOMException);
  NodeList                  getElementsByTagName(in DOMString name);
  void                      normalize();
};