function createXmlHttpRequestObject(){
  var xmlHttp;
  
  try {
  	xmlHttp=new XMLHttpRequest();  
  } catch(e){
    var XmlHttpVersions = new Array ("MSXML2.XMLHTTP.6.0",
									"MSXML2.XMLHTTP.5.0",
									"MSXML2.XMLHTTP.4.0",
									"MSXML2.XMLHTTP.3.0",
									"MSXML2.XMLHTTP",
									"Microsoft.XMLHTTP");
	for(var i=0; i<XmlHttpVersions.length && !xmlHttp; i++){
	  try {
	    xmlHttp = new ActiveXObject(XmlHttpVersions[i]);
	  } catch(e){}
	}
  }
  
  if(!xmlHttp){
    alert("Fehler bei der Erzeugung des XMLHTTPREQUESTOBJEKTS.");
  } else {
    return xmlHttp;
  }
}