function popUpPhoto(itemId,photoId) {
	var width = 600;
	var height = 400;
	var left = (screen.availWidth - width) / 2;
	var top = (screen.availHeight - height) / 2;
	var url = 'show_photo.php?itemId=' + itemId + '&photoId=' + photoId;
	window.open(url,'','width='+width+',height='+height+',left='+left+',top='+top+',scrollbars=yes,resizable=yes');
}