.curved {
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
    behavior:url(border-radius.htc);
}
#alert {
	width: 800px;
	background-image:url('fondo_bloques1.png');
	border: #000000 solid 0px;
	clear: both;
}
#alert2 {
	width: 1000px;
	background-image:url('fondo_bloques1.png');
	border: #000000 solid 0px;
	clear: both;
}
#alert3 {
	width: 400px;
	background-image:url('fondo_bloques1.png');
	border: #000000 solid 0px;
	clear: both;
}