问题：关于坛友的一个定时重复显示和隐藏div的实现

需求：打开页面只看到DIV2，等完秒数之后在显示DIV3。手动关闭DIV3后在重新数秒

我设置的间隔时间是3秒，代码如下：

html+css:

1: <!DOCTYPE HTML>

html>

head>

meta http-equiv="content-type" content="text/html;charset=utf-8">

title>Test</title>

style type="text/css">

   8:         height: 300px;

  10:         margin:0 auto;

  12:       }

  14:         margin:10px;

  16:       .div2{

  18:         height: 100px;

  20:       }

  22:         border: 1px dashed red;

  24:         height: 100px;

  26:       }

style>

head>

body>

div class="div1" id="div1">这是div1

<span id="showTime"></span> -->

div class="div2" id="div2">这是div2</div>

div class="div3" id="div3">这是div3

button id="closeDiv3">关闭div3</button>

div>

div>

body>

html>

js:

1: window.onload =function() {

   3:        var div2 = document.getElementById("div2");

   5:        var closeDiv3 = document.getElementById('closeDiv3');

7:

   9:        var countTime = 6;

  11:        function controlTime()

  13:          /*showTime.innerHTML = countTime +"秒后div2隐藏,div3显示";*/

  15:          countTime--;

  17:          {

  19:            div2.style.display = "none";

  21:            /*showTime.innerHTML = countTime1 +"秒后div3隐藏,div2显示";*/

  23:            {

  25:              div3.style.display = "none";

  27:            }

  29:        }

  31:        div3.onmouseover = function(){

  33:          closeDiv3.onclick = function(){

  35:            div3.style.display = "none";

  37:            /*showTime.innerHTML = countTime+"秒后div2隐藏,div3显示";*/

  39:        }

  40:       }

效果截图：