#iw {
	display: none;
	position: fixed;
	width: 100%;
	height: 100%;
	top: 0;
	left: 0;
	background: rgba(0,0,0,.5);
	overflow-y: auto;
	z-index: 1000;
}

#iw > div {
	position: relative;
	width: 500px;
	height: 500px;
	margin: 0px auto;
	background: #fff;
	box-shadow: 0 0 20px rgba(0,0,0, 0.5);
	z-index: 1001;
}