导航栏的制作怎么这样了啊？
.nav{
height:40px;
}
.nav_left{
width:10px;
background:url("images/nav_left.jpg") no-repeat;
height:40px;
float:left;
}
.nav_mid{
width:980px;
background:url("images/nav_bg.jpg") repeat-x;
float:left;
height:40px;
}
.nav_right{
width:10px;
background:url("images/nav_right.jpg") no-repeat;
float:left;
height:40px;
}
<div class="nav">
<div class="nav_left"></div>
<div class="nav_mid">
<div class="nav_mid_left">
<ul>
<li><a href="#">首页</a></li>
<li><a href="list.html">关于慕课</a></li>
<li><a href="list.html">新闻动态</a></li>
<li><a href="list.html">课程中心</a></li>
<li><a href="list.html">在线课程</a></li>
<li><a href="list.html">人才招聘</a></li>
</ul>
</div>
<div class="nav_mid_right">
<form action="#" method="post">
<input type="text" />
</form>
</div>
</div> <!--nav_mid结束-->
<div class="nav_right"></div>
</div><!--nav结束-->
</div> <!--wrap结束-->
