div {
	margin-left: auto;
	margin-right: auto;
	margin-top: 100px;
	width: 720px;
}

a {
	display: block;
	float: left;
	margin-right: 20px;
	margin-bottom: 20px;
	width: 213px;
	height: 221px;
	border: solid 1px #000;
}

a.nedlawRF {
	background: transparent url('../img/NedlawRoofsBlack.jpg') center top no-repeat;
}

a.nedlawRF:hover {
	background-image: url('../img/NedlawRoofsWhite.jpg');
}

a.nedlawLR {
	background: transparent url('../img/NedlawLRBlack.jpg') center top no-repeat;
}

a.nedlawLR:hover {
	background-image: url('../img/NedlawLRWhite.jpg');
}

a.nedlawLW {
	background: transparent url('../img/NedlawLWBlack.jpg') center top no-repeat;
}

a.nedlawLW:hover {
	background-image: url('../img/NedlawLWWhite.jpg');
}