interface ElementObserver {
/* IID: { 0x17ddd8c2, 0xc5f8, 0x11d2, \
        { 0xa6, 0xae, 0x0, 0x10, 0x4b, 0xde, 0x60, 0x48 } } */

        void onSetAttribute(in Element element, in DOMString name, in DOMString value);
        void onRemoveAttribute(in Element element, in DOMString name);
        void onSetAttributeNode(in Element element, in Attr newAttr);
        void onRemoveAttributeNode(in Element element, in Attr oldAttr);
};
