function Ventana () {
  var height = 200;
  var width = 438;
  var str = "height=" + height + ",innerHeight=" + height;
  str += ",width=" + width + ",innerWidth=" + width;
  if (window.screen) {
    var ah = screen.availHeight ;
    var aw = screen.availWidth ;

    var xc = (aw - width) / 2;
    var yc = (ah - height) / 2;

    str += ",left=" + xc + ",screenX=" + xc;
    str += ",top=" + yc + ",screenY=" + yc;
  }
  str += ",resizable=0,scrollbars=0,toolbar=0,status=0";
  var abre=open('pop.html','almabel',str);
}