function changeContent (newContent, contentDestination, contentOptions) {
  uriToUse = newContent + '?' + contentOptions;
  if (window.XMLHttpRequest) {
    xmlHttp = new XMLHttpRequest();
    xmlHttp.open("GET", uriToUse, false);
    xmlHttp.send(null);
  } else {
    var xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    xmlHttp.open("GET", uriToUse, false);
    xmlHttp.send();
  }
  if (contentDestination != '') {
    document.getElementById(contentDestination).innerHTML = xmlHttp.responseText;
  }
}