#ir_portal{
	display: block;
	height: 230px;
	width: 900px;
	overflow: hidden;
	position: relative;
}

#ir_default{
	position: absolute;
	z-index: 0;
}

.irLink{
	display: block;
	position: absolute;
	height: 20px;
	width: 15px;
	border: 1px solid black;
	background-color: #999;
	line-height: 20px;
	text-align: center;
	cursor: pointer;
	z-index: 100;
}