function img_popup(adresse,imgw,imgh) {
                winl = (screen.width - imgw) / 2;
                wint = (screen.height - imgh) / 2;
                window.open(adresse,'img_popup','toolbar=0,location=0,directories=0,status=0,scrollbars=0,resizable=0,menuBar=0,top='+wint+',left='+winl+',width='+imgw+',height='+imgh+'');
}
function postcards_popup(adresse) {
				w = 578;
				h = 450;
                winl = (screen.width - w) / 2;
                wint = (screen.height - h) / 2;
                window.open(adresse,'postcards_popup','toolbar=0,location=0,directories=0,status=0,scrollbars=0,resizable=0,menuBar=0,top='+wint+',left='+winl+',width='+w+',height='+h+'');
}