日期:2014-05-17 浏览次数:20891 次
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<style>
body{
    margin: 0px;
    padding: 0px;
}
#box{
    margin-top: 500px;
    margin-left: 200px;
}
#top{
    margin-top: 100px;
    margin-left: 300px;
}
#bottom{
    margin-top: 1240px;
    margin-left: 300px;
}
#sig{
    height: 20px;
    width: 90px;
    margin-left: 100px;
    margin-top: 100px;
    background-color: #0066FF;
    font-weight: bold;
    color: #FFFFFF;
}
#ajax{
    background-color: #CCCCCC;
    position: absolute;
    z-index: 9999;
    left: 0px;
    top: 0px;
    right: 0px;
    bottom: 0px;
}
</style>
</head>
<body>
<div onclick="ec()" id="sig">点击注册</div>
<div id="top">
求这能看到(要求灰色背景在的前提下)
</div>
<div id="box">
求这能看到(要求灰色背景在的前提下)
</div>
<div id="bottom">
求这也能看到
</div>
</body>
<script>
function $(x){ return document.getElementById(x);}
function ec() {
if($('ajax')){
$('ajax').parentNode.removeChild($('ajax'));
}
  var div = document.createElement("div")
  div.setAttribute("id", "ajax");
  div.style.height =document.body.clientHeight+"px"; //定位
  div.style.width =document.body.clientWidth+"px";
  document.body.appendChild(div);
  $('ajax').innerHTML="<b>aaaaaaaaaaaaaaaa </b>"
  }
</script>
</html>