JS利用cookies设置每隔24小时弹出框

function cookieGO(name) { 
 var today = new Date(); 
 var expires = new Date(); 
 expires.setTime(today.getTime() + 1000*60*60*24); 
 setCookie("cookievalue", name, expires); 
 } 
 function setCookie(name, value, expire) {  
 window.document.cookie = name + "=" + escape(value) + ((expire == null) ? "" : ("; expires=" + expire.toGMTString())); 
 } 
 function getCookie(Name) {  
 var findcookie = Name + "="; 
 if (window.document.cookie.length > 0) { // if there are any cookies 
  offset = window.document.cookie.indexOf(findcookie); 
 if (offset != -1) { // cookie exists 存在 
  offset += findcookie.length;   // set index of beginning of value 
  end = window.document.cookie.indexOf(";", offset)   // set index of end of cookie value 
  if (end == -1) 
  end = window.document.cookie.length; 
  return unescape(window.document.cookie.substring(offset, end)); 
  } 
 } 
 return null; 
 } 
 //提示过期弹框 
 if({$remindflag} == "1"){ 
  setInterval(function TanChuang() { 
  var c = getCookie("cookievalue"); 
  if (c != null) { 
   return; 
  } 
  cookieGO("getcookie"); 
   G.alert({ 
    "title":"过期提示", 
    "pclass":"box", 
    "text":"您的错题本服务将于"+"{$userinfo.member_end}"+"过期
为了不影响您的正常使用请续费", 
    "btnText":"购买续费", 
    "alert":function(){ 
     this._remove(); 
     window.location.href = "/manage/pay/readyopenvip.php"; 
    } 
   }); 
  },2000); 
 }