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)
		{		
 
		  document.getElementById('load_id').innerHTML = "<img src='images/working.gif'>";
		  //display_info(xmlhttp1.responseText);
  
		}
		//<img src="images/working.gif">
		if (req.readyState == 4) 
		{
			// only if 'OK'
			if (req.status == 200) {
				document.getElementById('load_id').innerHTML='';
				eval(what);
			} else {
				alert('There was a problem retrieving the XML data: ' +
					req.responseText);
			}
		}
	
}