var http_request = false;
 
    function macheRequest(url) {
 
        http_request = false;
 
        if (window.XMLHttpRequest) { // Mozilla, Safari,...
            http_request = new XMLHttpRequest();
        } else if (window.ActiveXObject) { // IE
            try {
                http_request = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    http_request = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {}
            }
        }
 
        if (!http_request) {
            alert('Ende :( Kann keine XMLHTTP-Instanz erzeugen');
            return false;
        }
        http_request.open('GET', url, true);
        http_request.onreadystatechange = alertInhalt;
        http_request.send(null);
 
    }
 
    function alertInhalt() {
        if (http_request.readyState == 4) {
              var answer = http_request.responseText;
              if(document.getElementById("inhalt").innerHTML != answer){
                document.getElementById("inhalt").innerHTML = answer;
              }
              else{
                document.getElementById("inhalt").innerHTML = "";
              }
        }
 
    }
macheRequest('app_salon_counter.php');