var xmlhttp = new XMLHttpRequest();

function processAjax(id, url, from) {

m = from.innerHTML;
if(m == 'View last messages') {
  from.innerHTML = 'Hide last messages';
  document.getElementById(id).innerHTML = '<img src="/js/loading.gif" width="16" height="16" style="margin-right: 5px; position: relative; top: 3px;" /> Loading...';
} else {
  from.innerHTML = 'View last messages';
  document.getElementById(id).innerHTML = '';
  return;
}

xmlhttp.open("GET", url, true);
xmlhttp.send(null);

xmlhttp.onreadystatechange = function() {
  if (xmlhttp.readyState == 4) {
     document.getElementById(id).innerHTML = xmlhttp.responseText;
  }
}
}