function prepareGallery() {
  if (!document.getElementsByTagName) return false;
  if (!document.getElementById) return false;
  if (!document.getElementById("imagegallery")) return false;
  var gallery = document.getElementById("imagegallery");
  var links = gallery.getElementsByTagName("a");
  for ( var i=0; i < links.length; i++) {
    links[i].onclick = function() {
      return doPic(this);
    }
  }
}
window.onload=prepareGallery;
leftPos = 0;
topPos = 0;

if (screen) {
leftPos = (screen.width-640) / 2;
topPos = (screen.height-426) / 2;
}

var imgOn
function doPic(imgName){imgOn=(""+imgName);
myWindow=window.open("large.php?"+imgOn, "myWindow", "width=640,height=426,status=no,scrollbars=no,resizable=no,toolbar=no,menubar=no,left="+leftPos+",top="+topPos);
myWindow.focus();
return false;
}