sessionStorage
<script> if(!window.sessionStorage.getItem('storge')){ alert('mb119.com提醒您:如果遇到加载缓慢或是没加载成功请多刷新几次 手机演示用手机访问效果更好'); window.sessionStorage.setItem('storge','true') } </script>
localStorage
if(!window.localStorage.getItem('storge')){ alert('弹窗'); window.localStorage.setItem('storge','true') }