/*
 * Returns an new XMLHttpRequest object, or false if the browser
 * doesn't support it
 */
function getXMLHttpRequest()
{
  var xmlreq = false;

  // Create XMLHttpRequest object in non-Microsoft browsers
  if (window.XMLHttpRequest)
	{
    xmlreq = new XMLHttpRequest();
  }
	else if (window.ActiveXObject)
	{

    try
		{
      // Try to create XMLHttpRequest in later versions
      // of Internet Explorer
      xmlreq = new ActiveXObject("Msxml2.XMLHTTP");
    }
		catch (e1)
		{
      // Failed to create required ActiveXObject
      try
			{
        // Try version supported by older versions
        // of Internet Explorer
        xmlreq = new ActiveXObject("Microsoft.XMLHTTP");
      }
			catch (e2)
			{
				// Unable to create an XMLHttpRequest by any means
        xmlreq = false;
      }
    }
  }

	return xmlreq;
}

/*
* Returns a function that waits for the specified XMLHttpRequest
* to complete, then passes it XML response to the given handler function.
 * req - The XMLHttpRequest whose state is changing
 * responseXmlHandler - Function to pass the XML response to
 */
function getReadyStateHandler(req, responseXmlHandler) {

  // Return an anonymous function that listens to the XMLHttpRequest instance
  return function () {

    // If the request's status is "complete"
    if (req.readyState == 4) {
      
      // Check that we received a successful response from the server
      if (req.status == 200) {

        // Pass the XML payload of the response to the handler function.
        responseXmlHandler(req.responseXML);

      }
			else
			{
				//location.reload(true);
        // An HTTP problem has occurred
        alert("HTTP error "+req.status+": "+req.statusText);
      }
    }
  }
}