// AJAX to display graphs
function displayResults(URL) {
  xmlhttp=GetXmlHttpObject();
  if (xmlhttp==null) {
    alert ("Your browser does not support HTTP Request");
    return;
  }
  xmlhttp.onreadystatechange=stateChanged;
  xmlhttp.open("GET",URL,true);
  document.getElementById("content").innerHTML='';
  document.getElementById("content").style.background="#FFFFFF url(images/loading.gif) no-repeat center"
  xmlhttp.send(null);
}

function stateChanged() {
  if (xmlhttp.readyState==4) {
    document.getElementById("content").style.backgroundImage="none";
    document.getElementById("content").innerHTML=xmlhttp.responseText;
  }
}

function GetXmlHttpObject() {
  if (window.XMLHttpRequest) {
    // code for IE7+, Firefox, Chrome, Opera, Safari
    return new XMLHttpRequest();
  }
  if (window.ActiveXObject) {
    // code for IE6, IE5
    return new ActiveXObject("Microsoft.XMLHTTP");
  }
  return null;
}