window.onload = prepareForm;

function getHTTPObject(){
 var xhr = false;
 if(window.XMLHttpRequest){
 xhr = new XMLHttpRequest();
 }
 else if (window.ActiveXObject){
  try {
   xhr = new ActiveXObject("Msxml2.XMLHTTP");
  } catch(e){
   try {
    xhr = new ActiveXObject("Microsoft.XMLHTTP"); 
   } catch(e) {
   xhr = false;
   }
  } 
 }
 return xhr;
}

function sendData(data) {
 var request = getHTTPObject();
 if(request) {
  displayLoading(document.getElementById("loading"));
  request.onreadystatechange = function () {
  parseResponse(request);
  };
  request.open("POST", "contact.php", true);
  request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
  request.send(data);
  return true;
 } else {
 return false;
 }
}


function parseResponse(request) {
 if(request.readyState == 4) {
  if(request.status==200 || request.status == 304) {
  var container = document.getElementById("container");
  container.innerHTML = request.responseText;
  var loading = document.getElementById("loading");
  loading.innerHTML = "";
  prepareForm();
  }
 }
}


function prepareForm() {
 if(!document.getElementById){
  return;
 }
 if(!document.getElementById("contact")){
 return;
 }
 
 document.getElementById("contact").onsubmit = function() {
 var data = "";
  for(var i=0; i<this.elements.length; i++){
  data += this.elements[i].name;
  data += "=";
  data += escape(this.elements[i].value);
  data += "&";
  }
  return !sendData(data);
 };
}

function displayLoading(element) {
 var image = document.createElement("img");
 image.setAttribute("src","../images/progressbar.gif");
 image.setAttribute("alt", "Loading...");
 element.appendChild(image);
}