*{
	margin: 0; 
	padding: 0;
}
ul{
	list-style: none;
}
#container{
	width: 560px;
	height: 420px;
	margin: 50px auto;
	position: relative;
	overflow: hidden;
}
#tab li{
	width: 20px;
	height: 20px;
	background: #000;
	color: #fff;
	float: left;
	margin-right: 5px;
	text-align: center;
	line-height: 20px;
	cursor: pointer;
	filter: Alpha(opacity=50); 
	opacity: 0.5;
}
#tab{
	position: absolute;
	right: 10px;
	bottom: 10px;
}
#tab .selected{
	background: orange;
}
#content img{
	display: none;
}
#content .selected{
	display: block;
}
#arrow{
	position: absolute;
	left: 10px;
	bottom: 10px;}
#arrow span{
	float: left;
	width: 20px;
	height: 20px;
	background: #000;
	color: #fff;
	text-align: center;
	line-height: 20px;
	margin-right: 5px;
	cursor: pointer;f
	ilter: Alpha(opacity=50); 
	opacity: 0.5;
}