function Xml()
{
     this.SendRequest = function(url, callback, postData)
     {
          var req = createXMLHTTPObject();
          if (!req) return;
          
          var method = (postData) ? "POST" : "GET";
          req.open(method, url, true);
          req.setRequestHeader('User-Agent', 'XMLHTTP/1.0');
          
          if (postData)
          {
               req.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
          }
          
          req.onreadystatechange = function()
          {
               if (req.readyState != 4) return;
               if (req.status != 200 && req.status != 304)
               {
                    //alert('HTTP error ' + req.status);
                    return;
               }
               callback(req);
          }
          if (req.readyState == 4) return;
          req.send(postData);
     }

     var XMLHttpFactories = [
          function() { return new XMLHttpRequest() },
          function() { return new ActiveXObject("Msxml2.XMLHTTP") },
          function() { return new ActiveXObject("Msxml3.XMLHTTP") },
          function() { return new ActiveXObject("Microsoft.XMLHTTP") }
     ];

     function createXMLHTTPObject()
     {
          var xmlhttp = false;
          for (var i = 0; i < XMLHttpFactories.length; i++)
          {
               try
               {
                    xmlhttp = XMLHttpFactories[i]();
               }
               catch (e)
               {
                    continue;
               }
               break;
          }
          return xmlhttp;
     }

}