只能看到中间的，上下的边框为什么看不到？？？
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>网页布局</title>
<style type="text/css">
*{margin:0;padding:0;}
#wrap{width: 980px;margin: 0 auto;}
#header{width：100%;height: 200px;boder:1px solid red;}
#mainbody{height: 200px;boder:1px solid blue;}
#footer{height: 200px;boder:1px solid green;}
.content{border: 4px solid black;padding: 27px 20px 20px;width:980px;}
.book{background: url(http://pic28.nipic.com/20130422/7278647_200808529196_2.jpg)no-repeat;}
img{margin:10px 18px;border:1px solid black;}
</style>
</head>
<body>
<div id="wrap">
<div id="header"></div>
<div id="mainbody">
<div class="content book">
<img src="http://pic2.ooopic.com/10/51/63/13b1OOOPIC17.jpg" width="100" height="100" >
<img src="http://www.zjjred.com/UpFiles/Picture/zjjred/2011031213205880528.jpg" width="100" height="100">
<img src="http://imga1.pic21.com/bizhi/140211/07369/s15.jpg" width="100" height="100">
<img src="http://pic12.nipic.com/20101222/2409453_174848073108_2.jpg" width="100" height="100">
<img src="http://imga1.pic21.com/bizhi/131217/05358/s14.jpg" width="100" height="100">
</div>
<div id="footer"></div>
</div>
</body>
</html>
