function ajaxtester(){ 
this.nav          = window.navigator.userAgent.toString().toLowerCase();
this.isMSIE_6     = this.nav.indexOf("msie 6.0") > -1 && this.nav.indexOf("opera") == -1;
this.ajax_support = true;

  if (typeof ajaxtester._initialized == "undefined") {

    ajaxtester.prototype.test = function () {
      if (this.isMSIE_6){
        var versions = ["MSXML2.XmlHttp.6.0", "MSXML2.XmlHttp.3.0"];
        for (var i=0; i < versions.length; i++) {  
          try {
              new ActiveXObject(versions[i]);
              XMLHTTP_VER = versions[i];
              break;
          } catch (oError) { 
            this.ajax_support = false; //NO ACTIVE X in IE 6
          } 
        }
      } else {
        if (typeof XMLHttpRequest == "undefined"){
          ajax_support = false;
        }    
      }
    };

    
    
    ajaxtester._initialized = true;
  } 
}