function ventanaPseudomodal(url, height, width, name, parms)
{
   var left = Math.floor( (screen.width - width) / 2);
   var top = Math.floor( (screen.height - height) / 2);
   var winParms = "top=" + top + ",left=" + left + ",height=" + height + ",width=" + width;
   if (parms)
   {
      winParms += "," + parms;
   }
   var win = window.open(url, name, winParms);
   return win;
}