function uploadMessages(pendingMessages, messageResponseHandler) {
  var messageTags = "";
  for (messageId in pendingMessages) {
    var initialServerMessage = $(messageId).serverMessage;
    messageTags += "<message>";
    messageTags += "<id>" + messageId + "</id>";
    messageTags += "<lastAuthor>" + $("authorIdSpec").value + "</lastAuthor>";
    messageTags += "<ranking>" + initialServerMessage.ranking + "</ranking>";
    messageTags += "<content>" + escape($(messageId).value) + "</content>";
    messageTags += "</message>";

    $(messageId).style.backgroundColor = "#cccccc";
  }

  var changeSpec = "<messages>" + messageTags + "</messages>";
  ajaxCaller.postBody
    ("content.phtml", null, messageResponseHandler, true, null,
     "text/xml", changeSpec);

}