body {
	text-align: center;
	background-color: #000;
}

.main {
	width:225px;
	height:276px;
	margin-left:auto;
	margin-right: auto;
	margin-top:20%;	
	background: url("bz_nc.jpg") no-repeat;
    display: inline-block;
}

.main:hover {
	background: url("bz_nc_up.jpg") no-repeat;
    display: inline-block;
}