function calnacti(mes,rok, prefix) {
        var http_request = false;

        if (window.XMLHttpRequest) {
            http_request = new XMLHttpRequest();
        } else if (window.ActiveXObject) {
            try {
              http_request = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (eror) {
              http_request = new ActiveXObject("Microsoft.XMLHTTP");
            }
        }

        http_request.onreadystatechange = function() { calvypln(http_request, prefix); };
        url = 'inc/cal.php?ajax=1&prefix='+prefix+'&mon='+mes+'&year='+rok;
        //alert(url);
        http_request.open('GET', url, true);
        http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
        http_request.send(null);
   }

    function calvypln(http_request, prefix) {
        if (http_request.readyState == 4) {
            if (http_request.status == 200) {    
                eval(http_request.responseText);           
                fillCalendar(prefix,ajaxdny);
                eval(prefix+"month="+ajaxmon+";");
                //alert(ajaxmon);
                eval(prefix+"year="+ajaxyear+";");
                //alert(ajaxyear);
                document.getElementById(prefix+"mesic").innerHTML = ajaxmonnazev;
                document.getElementById(prefix+"rok").innerHTML = ajaxyear;
            } else {               
            }
        }
    }