function decode () {
  var divs = document.getElementsByTagName('div');
  for(var i = 0; i < divs.length; i++) { 
    var div = divs[i];
    if (div.className == "encoded") {
      div.innerHTML = div.firstChild.nodeValue;
      changeBaseUrl(div);
    }
  }
}

function changeBaseUrl(e) {
   if (e.nodeName.toLowerCase() == "img") {
   var src = e.src;
   e.src = "/";
   if (src.indexOf(e.src) == 0) {
      e.src = "http://www.la-grange.net/" + src.substring(e.src.length);
    } else {
      e.src = src;
    }
  } else {
    if (e.hasChildNodes)
      for (var i = 0; i < e.childNodes.length; i++ ) {
        changeBaseUrl(e.childNodes[i]);
      }
  }
}