html,body {
 	font: 14px/18px arial, lucida grande, helvetica, sans-serif;
 	width: 100%;
	height: 100%;
	margin: 0;
}

.block {
	border: 1px solid #CCCCCC;
	position: relative;
	top: 0px;
	left: 0px;
	width:300px;
	height: 250px;
	padding: 15px;
}
.tl, .tr, .br, .bl {
	background-image: url(block_gris_corners.png);
	font-size: 1%;
	position: absolute;
	width: 6px;
	height: 6px;
	z-index: 5;
}
.tl {
	background-position: left top;
	left: -1px;
	top: -1px;
}
.tr {
	background-position: right top;
	right: -1px;
	top: -1px;
}
.br {
	background-position: right bottom;
	right: -1px;
	bottom: -1px;
}
.bl {
	background-position: left bottom;
	left: -1px;
	bottom: -1px;
}