function DoCallback(data)	{
	  // branch for native XMLHttpRequest object
  if	(window.XMLHttpRequest)	{
    req	=	new XMLHttpRequest();
    req.onreadystatechange	= processReqChange;
    req.open('POST', url,	true);
    req.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
    req.send(data);
// branch for IE/Windows ActiveX version
}
  else	if	(window.ActiveXObject)	{
    req	=	new ActiveXObject('Microsoft.XMLHTTP');
     if	(req)	{
      req.onreadystatechange	= processReqChange;
      req.open('POST', url,	true);
      req.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
      req.send(data);
              }
           }
}

function processReqChange()	{
  // only if req shows 'loaded'
   if	(req.readyState	==	4)	{
    // only if 'OK'
     if	(req.status	==	200)	{
       eval(what);
       }
     else	{
      alert('There was a problem retrieving the XML data: '	+ req.responseText);
      }
    }
}