function gen_request(handler,method,url,content) {
    req=null;
    if ( window.XMLHttpRequest ) {
        req = new XMLHttpRequest();
    } else if (window.ActiveXObject) {
        req=new ActiveXObject("Microsoft.XMLHTTP");
    }
    if (req == null) return false;
    req.onreadystatechange = function() {
        handler(req);
    }
    req.open("GET",url,true);
    req.send(content);
    return true;
}


function hodiny_obsluha(req) {
    if ( req.readyState==4 && req.status==200 ) {
        var data;
        if ( req.responseText == '' ) return false;
        try {
            eval( 'data='+req.responseText+';' );
        } catch(e){
            return false;
        }
        document.getElementById('hodiny').style.backgroundPosition = data['bgpos'];
        document.getElementById('hodiny').title = data['msg'];
        return true;
    }
}


function hodiny_pozadavek(secs) {
    if ( !gen_request(hodiny_obsluha, 'GET', gl_url_www+'www_base/hodiny.php', null )) {
        return false;
    }
    hodiny_settimeout(secs);
    return true;
}


function hodiny_settimeout(secs) {
    window.setTimeout("hodiny_pozadavek("+secs+")", secs*1000);
}


function hodiny_start(secs) {
    document.getElementById('hodiny').style.backgroundImage = "url('"+gl_url_www+"www_base/img/hodiny.png')";
    hodiny_pozadavek(secs);
}