function NewWindow(ev, windowUri, windowWidth, windowHeight, scrollbar) {
  var centerWidth = (window.screen.width - windowWidth) / 2;
  var centerHeight = (window.screen.height - windowHeight) / 2;

  newWindow = window.open(windowUri, "",
      "location=no,directories=no,status=no,menubar=no,toolbar=no,resizable=no" +
      ",scrollbars=" + scrollbar +
      ",width=" + windowWidth +
      ",height=" + windowHeight +
      ",left=" + centerWidth +
      ",top=" + centerHeight) +
      "";
  return false;
}