function getXmlHttpRequestObject()  
{ 
  // will store the reference to the XMLHttpRequest object 
  var xmlHttp = null; 
  // this should work for all browsers except IE6 and older 
  try 
  { 
    // try to create XMLHttpRequest object 
    xmlHttp = new XMLHttpRequest(); 
  } 
  catch(e) 
  { 
    // assume IE6 or older 
    var XmlHttpVersions = new Array("MSXML2.XMLHTTP.6.0", 
                                    "MSXML2.XMLHTTP.5.0", 
                                    "MSXML2.XMLHTTP.4.0", 
                                    "MSXML2.XMLHTTP.3.0", 
                                    "MSXML2.XMLHTTP", 
                                    "Microsoft.XMLHTTP"); 
    // try every prog id until one works 
    for (var i=0; i<XmlHttpVersions.length && !xmlHttp; i++)  
    { 
      try  
      {  
        // try to create XMLHttpRequest object 
        xmlHttp = new ActiveXObject(XmlHttpVersions[i]); 
      }  
      catch (e) {} 
    } 
  } 
  // return the created object or display an error message 
  
    return xmlHttp; 
}