function init_ajax() {
	var ajax;
	var msxmlhttp = new Array('Msxml2.XMLHTTP.3.0','Msxml2.XMLHTTP','Microsoft.XMLHTTP'); //'Msxml2.XMLHTTP.5.0','Msxml2.XMLHTTP.4.0'
	for (var i = 0; i < msxmlhttp.length; i++) {
		try {
			ajax = new ActiveXObject(msxmlhttp[i]);
		} catch (e) { ajax = null; }
	}
	if(!ajax && typeof XMLHttpRequest != "undefined")
		ajax = new XMLHttpRequest();
	return ajax;
}
function send_request(obsluha, method, url, content, headers) { 
	xmlhttp = init_ajax();
	if (xmlhttp == null) {
		alert('Cannot create XMLHTTP instance');
		return false;
	}
	xmlhttp.open(method, url); 
	
	xmlhttp.setRequestHeader("Method", method + " " + url + " HTTP/1.1");
//	xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	xmlhttp.onreadystatechange = function() { 
		obsluha(xmlhttp); 
	}; 
	if (headers) { 
		for (var key in headers) { 
			xmlhttp.setRequestHeader(key, headers[key]); 
		} 
	} 
	xmlhttp.send(content); 
	return true; 
}


function ajax_example(hlas) { 
	// odeslání požadavku
	if (!send_request(anketa_obsluha, 'GET', 'rpc.php?par=' + hlas)) { 
		return false; 
	} 
	document.getElementById('stav-anketa').innerHTML = 'Ukládá se'; 
	return true; 
}


function ajax_example_obsluha(xmlhttp) { 
	if (xmlhttp.readyState == 4 && xmlhttp.status == 200) { 
		// aktualizace odpovědí na základě aktuálního stavu  
		var odpovedi = xmlhttp.responseXML.getElementsByTagName('odpoved'); 
		for (var i=0; i < odpovedi.length; i++) { 
			document.getElementById(odpovedi[i].getAttribute('id')).innerHTML = odpovedi[i].firstChild.data; 
		} 
		document.getElementById('stav-anketa').innerHTML = 'Uloženo'; 
	} 
}