cobaia {
	background-color: #000000;
}

#layer1 {
	background-color: #ccc;
	border: 1px solid #000;
	padding: 10px;
	position: absolute;
	left: 50%;
	top: 70%;
	margin-top: -30px; /* make this half your image/element height */
	margin-left: -30pt; /* make this half your image/element width */
}

#close {
	float: right;
}