var str = "JS_On";
var xmlReq = null;
if (typeof window.ActiveXObject != 'undefined' ) {
    xmlReq = new ActiveXObject("Microsoft.XMLHTTP");
} else {
    xmlReq = new XMLHttpRequest();
}
var url = "http://www.pagony.hu/setjs.php";
xmlReq.open("POST",url,true);
xmlReq.send(str);