* {
	margin:0;
	padding:0
}
.aa {
	width:600px;
	height:250px;
	border:3px #a0a solid;
	margin:100px;
	position:relative;
	overflow:hidden
}
.aa ul {
	position:absolute;
	left:0;
	top:0;
}
.aa li {
	list-style:none;
	float:left;
	width:200px;
	height:250px;
}
.aa li img {
	width:200px;
	height:250px
}
.aa .left,.aa .right {
	position:absolute;
	top:100px;
	width:30px;
	height:50px;
	text-align:center;
	background:#000;
	color:#FFF;
	line-height:50px;
	font-size:40px;
	display:none;
	cursor:pointer
}
.aa .left {
	left:0
}
.aa .right {
	right:0
}