This javascript setTimeout interacts with ajax requests in a really weird way
function progres_import() {
//if(import_status != 'finalizat') {
    alert("progres_import");
    setTimeout(function() { return update_progres_import(); }, 2000);
    setTimeout(function() { return update_progres_import(); }, 4000);
    setTimeout(function() { return update_progres_import(); }, 6000);
    setTimeout(function() { return update_progres_import(); }, 8000);

    //setTimeout(function() { progres_import(); }, 400);
//}
//else {

//}
}

var xmlhttp_import_progres;
function update_progres_import() {
xmlhttp_import_progres=GetXMLHttpObject();
if (xmlhttp_import_progres==null) {
    alert ("Browser does not support HTTP Request (xmlhttp_import_progres)");
    return;
}

var url="crm/ferestre/import_progres.php";
url=url+"?sid="+Math.random();

xmlhttp_import_progres.onreadystatechange=function() {
    if (xmlhttp_import_progres.readyState == 4) {
        progres_resp = xmlhttp_import_progres.responseText;
        progres = progres_resp.split('_');
        import_nrc = progres[0];
        import_nrt = progres[1];
        import_status = progres[2];
        mesaj = 'Progres import: ' + import_nrc + ' / ' + import_nrt;
        //document.getElementById("corp_import_mesaj").innerHTML = mesaj;
        alert(progres_resp);
    }
};
xmlhttp_import_progres.open("POST",url,true);
xmlhttp_import_progres.send(null);
}

function progres_import() {
//if(import_status != 'finalizat') {
    alert("progres_import");
    setTimeout(function() { return update_progres_import(0); }, 2000);
    setTimeout(function() { return update_progres_import(1); }, 4000);
    setTimeout(function() { return update_progres_import(2); }, 6000);
    setTimeout(function() { return update_progres_import(3); }, 8000);

    //setTimeout(function() { progres_import(); }, 400);
//}
//else {

//}
}

var xmlhttp_import_progres = [];
function update_progres_import(i) {
    xmlhttp_import_progres[i]= GetXMLHttpObject();
    if (xmlhttp_import_progres[i]==null) {
        alert ("Browser does not support HTTP Request (xmlhttp_import_progres)");
        return;
    }

    var url="crm/ferestre/import_progres.php";
    url=url+"?sid="+Math.random();

    xmlhttp_import_progres[i].onreadystatechange=function() {
        if (xmlhttp_import_progres[i].readyState == 4) {
            progres_resp = xmlhttp_import_progres[i].responseText;
            progres = progres_resp.split('_');
            import_nrc = progres[0];
            import_nrt = progres[1];
            import_status = progres[2];
            mesaj = 'Progres import: ' + import_nrc + ' / ' + import_nrt;
            //document.getElementById("corp_import_mesaj").innerHTML = mesaj;
            alert(progres_resp);
        }
    };
    xmlhttp_import_progres[i].open("POST",url,true);
    xmlhttp_import_progres[i].send(null);
}