.estilo_botao a {
	padding:0px;
	text-decoration: none;
	text-align:center;
	color:#999999; 
	background: #ffffff url(b1.jpg);
	width:160px;
	height:35px;
	display:block;
	font-family: verdana, arial, helvetica, sans-aerif;
	font-size: 11px;
	line-height: 35px;
	font-weight: bold;
} 

.estilo_botao a:hover {
	padding:0px;
	text-decoration: none;
	text-align:center;
	color:#000000; 
	background: #ffffff url(b2.jpg);
	width:160px;
	height:35px;
	display:block;
	font-family: verdana, arial, helvetica, sans-aerif;
	font-size: 11px;
	line-height: 35px;
	font-weight: bold;
}