
  function popImage(imageURL, title)
  {
    if (document.getElementById && navigator.userAgent.toLowerCase().indexOf('opera') == -1)
    {
        var imgWin = window.open('about:blank', 'popup','width=200, height=200, left=100, top=100');

        with (imgWin.document)
        {
            writeln('<html><head><title>Loading ...</title>');
            writeln('<style type="text/css"><!-- body { margin: 0px; } --></style></head>');
            writeln('<body onload="self.focus();">');
            writeln('<a href="#" onClick="window.close();" title="Zavøít okno.">');
            writeln('<img class="a" id="obr" style="display:none; border: 0px;"/></a></body></html>');
            close();
        }

        var img = new Image();
        img.src = imageURL;
        img.onload = function() { sizeImgWin(imgWin, img, title); };
    }
    else window.open(imageURL, title);
  }

  function sizeImgWin(win, img, title)
  {
      var new_w = img.width;
      var new_h = img.height;
      var old_w = win.innerWidth || win.document.body.offsetWidth;
      var old_h = win.innerHeight || win.document.body.offsetHeight;

      if (!new_w) { new_w = old_w; }
      if (!new_h) { new_h = old_h; }

      new_w -= old_w; new_h -= old_h;
      win.resizeBy(new_w,new_h);
      win.document.title = title;
      
      var pic = win.document.getElementById('obr');
      pic.src = img.src;
      pic.style.display = 'block';

      sw=screen.width;
      sh=screen.height;

      var leftPos=((sw-new_w)/2)-100; // Exactly centered.
      var topPos=((sh-new_h)/2)-(100+(((sh-new_h)/2)*0.1)); // Centered, then moved up 10%
      win.moveTo(leftPos, topPos);
  }
