var request = false;

function createRequest() {
  try {
    request = new XMLHttpRequest();
  } catch (trymicrosoft) {
    try {
      request = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (othermicrosoft) {
      try {
        request = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (failed) {
        request = false;
      }
    }
  }
}

createRequest();
go('atlas','');
function submitform() {
var parameters = "fio=" + encodeURI( document.getElementById('fio').value ) + "&email=" + encodeURI( document.getElementById('email').value) + "&desc=" + encodeURI( document.getElementById('desc').value ) + "&submit=" + encodeURI( document.getElementById('submit').value);
go('guestbook', parameters);
}
function go(page, parameters) {
document.getElementById("content").innerHTML = "<p>Подождите!</p> <p>Идет загрузка данных</p>";
if ((page == null) || (page == "")) return;
var url = "" + page + ".php";
request.open("POST", url, true);
request.onreadystatechange = function () {
 if (request.readyState == 4 && request.status == 200) {
         document.getElementById("content").innerHTML = request.responseText;
 }
}
request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
request.setRequestHeader("Content-length", parameters.length);
request.setRequestHeader("Connection", "close");
request.send(parameters);

}