var xmlHttp;

function vytvorXMLHttpRequest(){
    if (window.ActiveXObject){
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    } else if (window.XMLHttpRequest){
        xmlHttp = new XMLHttpRequest();
    }
}

function ajax(url,kam){
    
    vytvorXMLHttpRequest();
    xmlHttp.onreadystatechange = zpracujZmenuStavu;
    xmlHttp.open("GET", url, true);
    xmlHttp.send(null);
    
    function zpracujZmenuStavu(){
        if(xmlHttp.readyState == 4){
            if (xmlHttp.status == 200){
            document.getElementById(kam).innerHTML = xmlHttp.responseText;
            }
        }
    }
}