function AjaxClient()
{
  var browser = new Browser(); // The browser properties
  this.xmlhttp = null;
  if(browser.isIE()) {
    try       { this.xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");     }
    catch(e)  { this.xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");  }
  } else      { this.xmlhttp = new XMLHttpRequest();                    }
  this.sendRequest = function(url, cbFunction) {
    this.xmlhttp.open("GET", url, true);
    this.xmlhttp.send(null);
    this.xmlhttp.onreadystatechange = cbFunction;
  }
  this.getResponseText = function() { return this.xmlhttp.responseText; }
  this.isReady = function() { return (this.xmlhttp.readyState == 4); }
}