function objAjax()
{
    var xmlhttp=false;
    try {
        xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
        try {
           xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        } catch (E) {
            xmlhttp = false;
        }
    }

    if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
        xmlhttp = new XMLHttpRequest();
    }

    return xmlhttp;
}

function setupEnv(sn) {
    var requestObj = objAjax();
    requestObj.open("GET", "setup_env.php?e="+sn, true);
    requestObj.onreadystatechange = function() {
        if (requestObj.readyState == 4) {
            if (requestObj.responseText == 1)
                history.go(0);
        }
    }   
    requestObj.send(null);
}