.div_a
{
    width: 200px;
    margin: 20px auto 0 auto;
    height: 70px;
}
.button {
	display: inline-block;
	outline: none;
	cursor: pointer;
	text-align: center;
	text-decoration: none;
	font: 16px/100% 'Microsoft yahei',Arial, Helvetica, sans-serif;
	padding: .5em 2em .55em;
	text-shadow: 0 1px 1px rgba(0,0,0,.3);
	-webkit-border-radius: .5em; 
	-moz-border-radius: .5em;
	border-radius: .5em;
	-webkit-box-shadow: 0 1px 2px rgba(0,0,0,.2);
	-moz-box-shadow: 0 1px 2px rgba(0,0,0,.2);
	box-shadow: 0 1px 2px rgba(0,0,0,.2);
}
.button:hover {
	text-decoration: none;
}
.button:active {
	position: relative;
	top: 1px;
}
/* white */
.white {
	color: #606060;
	border: solid 1px #b7b7b7;
	background: #fff;
	background: -webkit-gradient(linear, left top, left bottom, from(#fff), to(#ededed));
	background: -moz-linear-gradient(top,  #fff,  #ededed);
	filter:  progid:DXImageTransform.Microsoft.gradient(startColorstr='#ffffff', endColorstr='#ededed');
}
.white:hover {
	background: #ededed;
	background: -webkit-gradient(linear, left top, left bottom, from(#fff), to(#dcdcdc));
	background: -moz-linear-gradient(top,  #fff,  #dcdcdc);
	filter:  progid:DXImageTransform.Microsoft.gradient(startColorstr='#ffffff', endColorstr='#dcdcdc');
}
.white:active {
	color: #999;
	background: -webkit-gradient(linear, left top, left bottom, from(#ededed), to(#fff));
	background: -moz-linear-gradient(top,  #ededed,  #fff);
	filter:  progid:DXImageTransform.Microsoft.gradient(startColorstr='#ededed', endColorstr='#ffffff');
}