/* Allgemeine Funktion fuer zentriertes Popup, idealerweise schreibt man aber eine eigene Wrapper-function fuer explizite Anwendung, siehe unten */
	function popupCenter(url, name, attributes, width, height) {
		topx = (screen.height - height) / 2;
		leftx = (screen.width - width) / 2;
		if (attributes.length > 0)
			if (attributes.substr(attributes.length-1,1) != ',')
				attributes += ','
		var w = window.open(url, name, attributes + 'width='+width+',height='+height+',screenx='+leftx+',screeny='+topx+',top='+topx+',left='+leftx+',status=yes,resizable=yes,scrollbars=yes');
		w.focus();
	}

	function popupBild(url) {
		popupCenter(url, 'popupbild', '', 640, 580);
		return false;
	}
	function popupserial(url) {
		popupCenter(url, 'popupserial', '', 820, 520);
		return false;
	}