documentUrl = window.location.href;
pos = documentUrl.lastIndexOf("_");
language = documentUrl.substring(pos+1, pos+3);
cookiestring = "used=" + language;

if (document.cookie.indexOf(cookiestring)==-1)
  {
   // First time page used, show layer & create temporary cookie
   document.cookie = cookiestring;
  }
else
  {
   // Page already used, hide layer
   document.getElementById('popup').style.visibility='hidden';
  }