function guest (MyPage, w, h, scrollbars)

{

  var win = null;

  var LeftPosition = (screen.width) ? (screen.width - w) / 2 : 0;

  var TopPosition = (screen.height) ? (screen.height - h) / 2 : 0;

  var Settings = 'height = ' + h + ', width = '+ w + ', top = ' + TopPosition + ', left = ' + LeftPosition + ', scrollbars = ' + scrollbars + ', toolbar = no, resizable = no, directories = no';

  win = window.open(MyPage, '', Settings);

  if (win.window.focus)

    win.window.focus();

}