var url = "./switch_user.php"; // The server-side script
function handleHttpResponse() {
  if (http.readyState == 4) {
    icona = document.getElementById("swico");

    if (http.responseText == 0) {
      icona.src="./logo/icons/switch_gray.png";
    } else {
      icona.src="./logo/icons/switch.png";
    }
    isWorking = false;
  }
}
var isWorking = false;
function updateCityState() {
  if (!isWorking && http) {
    http.open("GET", url, true);
    http.onreadystatechange = handleHttpResponse;
    isWorking = true;
    http.send(null);
  }
}
function getHTTPObject() {
  var xmlhttp;
  /*@cc_on
  @if (@_jscript_version >= 5)
    try {
      xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
      try {
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (E) {
        xmlhttp = false;
      }
    }
  @else
  xmlhttp = false;
  @end @*/
  if (!xmlhttp && typeof XMLHttpRequest != 'undefined') {
    try {
      xmlhttp = new XMLHttpRequest();
    } catch (e) {
      xmlhttp = false;
    }
  }
  return xmlhttp;
}
var http = getHTTPObject(); // We create the HTTP Object