function Ajax(doneHandler, failHandler) {
  newAjax = this;
  this.onDone = doneHandler;
  this.onFail = failHandler;
  this.transport = this.getTransport();
  this.transport.onreadystatechange = ajaxTrampoline(this);
}

Ajax.prototype.get = function (uri, query, sync) {
  sync = sync || false;
  if( typeof query != 'string' ) query = ajaxArrayToQueryString(query);
  URI = uri+(query ? ('?'+query) : '');
  this.transport.open('GET', URI, !sync );
  this.transport.setRequestHeader("If-Modified-Since", "Sat, 1 Jan 1972 00:00:00 GMT");
  this.transport.send('');
}

Ajax.prototype.post = function (uri, data, sync) {
  sync = sync || false;
  if( typeof data != 'string' ) data = ajaxArrayToQueryString(data);
  var post_form_id = ge('post_form_id');
  if (post_form_id) data += '&post_form_id='+post_form_id.value;
  this.transport.open('POST', uri, !sync);
  this.transport.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
  this.transport.setRequestHeader("If-Modified-Since", "Sat, 1 Jan 1972 00:00:00 GMT");
  this.transport.send(data);
}

Ajax.prototype.stateDispatch = function () {
  if( this.transport.readyState == 1 && this.showLoad ) ajaxShowLoadIndicator();
  
  if( this.transport.readyState == 4 ) {
    if( this.showLoad ) ajaxHideLoadIndicator();
    if( this.transport.status >= 200 && this.transport.status < 300 && this.transport.responseText.length > 0 ) {
      if( this.onDone ) this.onDone(this, this.transport.responseText);
    } else {
      if( this.onFail ) this.onFail(this);
    }
  }
}

Ajax.prototype.getTransport = function () {
  var ajax = null;
  
  try { ajax = new XMLHttpRequest(); }
  catch(e) { ajax = null; }
  
  try { if(!ajax) ajax = new ActiveXObject("Msxml2.XMLHTTP"); }
  catch(e) { ajax = null; }
  
  try { if(!ajax) ajax = new ActiveXObject("Microsoft.XMLHTTP"); }
  catch(e) { ajax = null; }
  
  return ajax;
}

function ajaxTrampoline(ajaxObject) {
  return function () { ajaxObject.stateDispatch(); };
}