function getCookie(){
  if(document.cookie.length>0){
    begin = document.cookie.indexOf("bron=");
    if(begin != -1){
    begin += 5;
    end = document.cookie.indexOf(";",begin);
    if (end == -1) end = document.cookie.length;
    return document.cookie.substring(begin, end);
    }
  }
  return null;
}

function setCookie(){
  document.cookie = "bron="+self.location.href;
}

function delCookie(){
  if(getCookie()){
    document.cookie = "bron=";
  }
}