http_request = false;
var cont_id;
var cont_url;
function ajax_call(url,id) {
  http_request = false;
  cont_id = id;
  cont_url = url;
  document.getElementById(cont_id).innerHTML= '<p align="center"><img src="../img/ajax-loader.gif"></p>';
  if (window.XMLHttpRequest) { // Mozilla, Safari,...
    http_request = new XMLHttpRequest();
    if (http_request.overrideMimeType) {
      http_request.overrideMimeType('text/xml');
       // zu dieser Zeile siehe weiter unten
    }
  } 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('Abfragefehler');
    return false;
  }
  http_request.onreadystatechange = alertme;
  http_request.open('GET', cont_url, true);
  http_request.send(null);
}
	
function alertme() {
  if (http_request.readyState == 4) {
    if (http_request.status == 200)	{document.getElementById(cont_id).innerHTML=http_request.responseText;}
    // else {alert('Error in Ajax');}
  }
}