.mainRight a,div,ul,li { padding: 0; margin: 0;list-style: none; }
img { border: 0; }
.roll { width: 320px; height: 150px; margin: auto 0; position: relative; top:30px;}
.btn_left { display: block; width: 30px; height: 50px; background: url(btnL.png) no-repeat; position:relative; top:50px; float:left;  z-index: 1; }
.btn_right { display: block; width: 30px; height: 50px; background: url(btnR.png) no-repeat; position:relative; top:50px; float:right;  z-index: 1; }
.roll .wrap { width: 260px; height: 150px; margin: 0 auto; position: relative; overflow: hidden; }
.roll ul { position: absolute; top: 0; left: 0; }
.roll li { float: left; width: auto; height: 200px; margin-left:30px; text-align: center; }
.roll li a:hover { position: relative;}