function createRequest() {
	var r = null;
	if (window.XMLHttpRequest) {		//Mozilla, Safari, ...
		r = new XMLHttpRequest();
		if (r.overrideMimeType) {
			r.overrideMimeType('text/xml');
		}
	}
	else if (window.ActiveXObject) {	//IE
		try {
			r = new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e) {
			try {
				r = new ActiveXObject("Microsoft.XMLHTTP");
			}
			catch (e) {}
		}
	}
	if (!r) {
		r = null;
		window.alert('Ich kann keinen XMLHttpRequest erstellen :(!');
	}
	return r;
}