function redirect(url, msg)
{
   var TARG_ID = "REDIRECT";
   var DEF_MSG = "www.GO-GPS.nl wordt geladen ...";
   if( ! msg )
   { msg = DEF_MSG;  }
   if( ! url )
   { throw new Error('"url" vergeten');  }
   var e = document.getElementById(TARG_ID);
   if( ! e )
   { throw new Error('"REDIRECT" element id not found'); }
   var cTicks = parseInt(e.innerHTML);
   var timer = setInterval(function()
   {
      if( cTicks )
      { e.innerHTML = --cTicks;  }
      else
      {  clearInterval(timer);
         document.body.innerHTML = msg;
         location = url; }
   }, 800);
}