function openWindowCentered(url,name,width,height) {
  var posX = (screen.width - width) / 2;
  var posY = (screen.height - height) / 2;
	var win = openWindow(url,name,width,height,posX,posY);
	return win;
}

function openWindow(url,name,width,height,posX,posY) {
	var popWindow=window.open(url,name,'left='+posX+',top='+posY+',width='+width+',height='+height+',scrollbars=yes,menubar=no,status=yes,resizable=yes')
	return popWindow;
}

function showGallerie(url) {
  var w = openWindowCentered(url,'Help',670,438);
  w.focus();
  return w;
}