var foto = '';
function popup(plik,x,y) {
var w = screen.width;
var h = screen.height;
foto  = plik;
var lpos = (w-x)/2;
var tpos = (h-y)/2;

var dane = "width=" + x + ",height=" + y +",top=" + tpos-100 + ",left=" + lpos-100 + ", status=no, scrollbars=no";

window.open('popup.html','obrazek',dane);
}