function changeImage(obj) {
       var path = "http://www.frankenbueffel.de/bilder/page/";

       if(path + "anfahrt_fern.jpg" == obj.src)
	obj.src = (path + "anfahrt_mittel.jpg");

       else if(path + "anfahrt_mittel.jpg" == obj.src)
	obj.src = (path + "anfahrt_nah.jpg");

       else
        obj.src = path + "anfahrt_fern.jpg";                                                      
   }