//
	// Define a list of Microsoft XML HTTP ProgIDs.
	//
	var XMLHTTPREQUEST_MS_PROGIDS = new Array(
	  "Msxml2.XMLHTTP.7.0",
	  "Msxml2.XMLHTTP.6.0",
	  "Msxml2.XMLHTTP.5.0",
	  "Msxml2.XMLHTTP.4.0",
	  "MSXML2.XMLHTTP.3.0",
	  "MSXML2.XMLHTTP",
	  "Microsoft.XMLHTTP"
	);
	
	//
	// Define ready state constants.
	//
	var XMLHTTPREQUEST_READY_STATE_UNINITIALIZED = 0;
	var XMLHTTPREQUEST_READY_STATE_LOADING       = 1;
	var XMLHTTPREQUEST_READY_STATE_LOADED        = 2;
	var XMLHTTPREQUEST_READY_STATE_INTERACTIVE   = 3;
	var XMLHTTPREQUEST_READY_STATE_COMPLETED     = 4;
	
	//
	// Returns XMLHttpRequest object.
	//
	function getXMLHttpRequest()
	{
	  var httpRequest = null;
	
	  // Create the appropriate HttpRequest object for the browser.
	  if (window.XMLHttpRequest != null)
	    httpRequest = new window.XMLHttpRequest();
	  else if (window.ActiveXObject != null)
	  {
	    // Must be IE, find the right ActiveXObject.
	    var success = false;
	    for (var i = 0;
	         i < XMLHTTPREQUEST_MS_PROGIDS.length && !success;
	         i++)
	    {
	      try
	      {
	        httpRequest = new ActiveXObject(XMLHTTPREQUEST_MS_PROGIDS[i]);
	        success = true;
	      }
	      catch (ex)
	      {}
	    }
	  }
	
	  // Display an error if we couldn't create one.
	  if (httpRequest == null)
	    alert("Error in HttpRequest():\n\n"
	      + "Cannot create an XMLHttpRequest object.");
	
	  // Return it.
	  return httpRequest;
	}
	
	var myXmlHttpRequest = getXMLHttpRequest();