css实现多张图片横向居中显示的方法

   <div class="main">
  <div class="tag">
   分类小贴士
  </div>
  <div class="images" >
   <div class="mid">
    <img src="images/06.jpg" />
   </div>
   <div class="mid">
    <img src="images/05.jpg" />
   </div>
   <div class="mid">
    <img src="images/07.jpg" />
   </div>
   <div class="mid">
    <img src="images/11.jpg" />
   </div>
   <div class="mid">
    <img src="images/14.jpg" />
   </div>
  </div>
  <div style="clear:both;"></div>
  <div style="margin-bottom:30px;">
  </div>

 .main{
  width:100%;
  margin-:40px;
 }
 .main .tag{
  margin:0 auto;
  width:200px;
  font-size:18px;
  border-bottom:1px solid #878787;
  text-align:center;
  margin-bottom:20px;
 }
 .main .images{ 
        margin:0 auto;
  width:1300px;//设置<div>块的大小，要实现居中效果需要经过计算
 }
 .main .images .mid{
     float: left;//设置左对齐
     margin:5px;//图片边缘间隔
 }  
 .main .images .mid img{
     width:250px;//规范图片长宽
     height:300px;
 }