function saveCookie(name, value){
    document.cookie=name+"="+value+"; path=/";
}

function getCookie(name){
  var c=document.cookie.split(';');
  for(var i=0; i<c.length; i++){
    var cdata=c[i].replace(/^\s+/, '');
    if (cdata.indexOf(name+'=')==0)
      return cdata.substring(name.length+1);
  }
  return null;
}

if(getCookie("referer")==null){ 
  saveCookie("referer",document.referrer);
}