function fotoalbum(cat,subcat,foto)
    {
    var popupwidth = 980, popupheight = 700 ;
    width = screen.width ;
    height = screen.height ;
    if (document.all)
        {
        width = document.body.clientWidth ;
        height = document.body.clientHeight ;
        }
    else if (document.layers)
        {
        width = window.innerWidth ;
        height = window.innerHeight ;
        }
    leftpos = (width-popupwidth)/2 ;
    toppos = (height-popupheight)/2 ;
    window.open("fotoalbum.php?cat="+cat+"&subcat="+subcat+"&foto="+foto,"_blank","toolbar=0,location=0,directories=0,status=0,menubar=0,resizable=0,width=980,height=700,scrollbars=0,top="+toppos+",left="+leftpos) ;
    }