.picBtnLeft{ width:668px; height:204px;  position:relative; z-index:0; overflow:hidden;} 
.picBtnLeft ul{padding:0;margin:0; list-style:none;}
.slider{position:absolute;z-index:0;cursor:pointer;top:0;left:0;}
.slider img{width:668px;height:204px;display:block;}
.num{position:absolute;z-index:1;left:0;bottom:0;}
.num li{float:left;width:80px;height:58px;cursor:pointer;overflow:hidden;margin-left:5px;}
.num li.on{width:80px;height:58px;}
.num li.li_1 {background:url(../images/banner_small_1.png) bottom no-repeat;}
.num li.on.li_1{background:url(../images/banner_small_11.png) bottom no-repeat;}

.num li.li_2 {background:url(../images/banner_small_2.png) bottom no-repeat;}
.num li.on.li_2{background:url(../images/banner_small_21.png) bottom no-repeat;}

.num li.li_3 {background:url(../images/banner_small_3.png) bottom no-repeat;}
.num li.on.li_3{background:url(../images/banner_small_31.png) bottom no-repeat;}

.num li.li_4 {background:url(../images/banner_small_4.png) bottom no-repeat;}
.num li.on.li_4{background:url(../images/banner_small_41.png) bottom no-repeat;}