function bildlupe(pic) {
 	var w = 750;
	var h = 570;
	var x = screen.availWidth/2-w/2;
	var y = screen.availHeight/2-h/2;
	var popupWindow = window.open(pic,'Bildlupe','width='+w+',height='+h+',left='+x+',top='+y+',screenX='+x+',screenY='+y+',scrollbars=no');
}