function createRequestObject() {
  var ro;
  var browser = navigator.appName;
  if(browser == "Microsoft Internet Explorer"){
    ro = new ActiveXObject("Microsoft.XMLHTTP");
  }else{
    ro = new XMLHttpRequest();
  }
  return ro;
}
 
var http = createRequestObject();
var divid;

function dowork(id, url) {
  divid = id;
  document.getElementById(id).innerHTML = '<div id="loader"><img src="http://www.moodo.de/image/loading.gif"></div>';
  http.open('get', url, true);
  http.onreadystatechange = handleResponse;
  http.send(null);
  return false;
}

function handleResponse(response) {
	if(http.readyState == 4){
        var response = http.responseText;
        document.getElementById(divid).innerHTML = response;
    }
}