javascript只弹出一次框再次刷新不弹出

.打开页面自动弹出当关闭弹框的时候设置cookie生存时间再次刷新页面判断cookie是否失效

<html>

<head>

<meta charset="utf-8" />

  <title>LIGHTBOX EXAMPLE</title>

  <style>

   .black_overlay{ display: none; position: absolute; top: 0%; left: 0%; width: 100%; height: 100%; background-color: black; z-index:1001; -moz-opacity: 0.6; opacity:.60; filter: alpha(opacity=60); }

   .white_content { display: none; position: absolute; top: 25%; left: 25%; width: 50%; height: 50%; /*padding: 16px;*/ /*border: 16px solid orange;*/border: 1px solid grey; background-color: white; z-index:1002; /*overflow: auto; */}

   </style>

   <script type="text/javascript" src="js/jquery-1.10.2.min.js"></script>

   <script>

　

   $( document).ready(function(){

//判断cookie是否存在

    if(document.cookie.length <=0){

       one();

     }else{

      return '';

     }

      });

   function one(){

     document.getElementById('light').style.display='block';

    document.getElementById('fade').style.display='block'

    }

   function two(){

    document.getElementById('light').style.display='none';

    document.getElementById('fade').style.display='none'

    //关闭弹框是设置cookie

    setCookie('opop','lailailai',1800)

       }

    //设置cookie

    function setCookie(cname, cvalue, exdays) {

     var d = new Date();

     d.setTime(d.getTime() + (exdays*24*60*60*1000));

     var expires = "expires="+d.toUTCString();

     document.cookie = cname + "=" + cvalue + "; " + expires;

    }

    //获取cookie

    function getCookie(cname) {

     var name = cname + "=";

     var ca = document.cookie.split(';');

     for(var i=0; i<ca.length; i++) {

      var c = ca[i];

      while (c.charAt(0)==' ') c = c.substring(1);

      if (c.indexOf(name) != -1) return c.substring(name.length, c.length);

     }

     return "";

    }

         </script>

</script>

</head>

<body >

  <p>

    <a href="javascript:showBg();" onclick="one()">点击这里打开窗口</a>

  </p>

  <div id="light" class="white_content">

   <img src="http://imageavatar.xiangsibang.com/gfs.php?img=9cdbc343a8846bba79b55a7c523f9b4f&w=800" style="width:100%;height:100%;">

    <a href="javascript:void(0)" onclick="two()" style="   color:red;margin-top: -50%; position: absolute;float: right;/* margin-right: -34%; */margin-left: 99%;">X</a>

  </div>

  <div id="fade" class="black_overlay" >

  </div>

</body>

</html>

弹出

javascript只弹出一次框 再次刷新不弹出

javascript只弹出一次框再次刷新不弹出