function openPopup(t,w,h) {
	ziel = t;
	h = h - 20; var x=0, y=0, parameter="";
	if (w < screen.availWidth || h < screen.availHeight) {
	x = (screen.availWidth - w - 12) / 2;
	y = (screen.availHeight - h - 104) / 2;
	if (window.opera) y = 0; // Opera positioniert unter den Symbolleisten
	if (x<0 || y<0) { x=0; y=0; }
		else parameter = "width=" + w + ",height=" + h + ",";
	}
	parameter += "left=" + x + ",top=" + y;
	parameter += ",menubar=no,location=no,toolbar=no,status=no";
	parameter += ",resizable=no,scrollbars=no";
	var Fenster = window.open(ziel,"PopUp",parameter);
	if (Fenster) Fenster.focus();
}