function send_xmlhttprequest(obsluha, method, url, content, headers)
{
    var xmlhttp = (window.XMLHttpRequest ? new XMLHttpRequest() : (window.ActiveXObject ? new ActiveXObject("Msxml2.XMLHTTP") : false));
    
    if (!xmlhttp) {
        return false;
    }
    
    xmlhttp.open(method, url,true);
    xmlhttp.onreadystatechange = function() {
        if(obsluha !=null)
        obsluha(xmlhttp, content);
    };
    if (headers) {
        for (var key in headers) {
            xmlhttp.setRequestHeader(key, headers[key]);
        }
    }
    xmlhttp.send(null);
    return true;
}