<head>
<style>
#myblock>div {
width:30%;
height: 50px;
border: 2px solid #000;
margin: 5px;
display: inline-block;
}
.active {
background-color: red;
}
</style>
<script type='text/javascript' src='http://code.jquery.com/jquery-1.9.1.js'></script>
</head>
<body>
<div id="myblock">
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
</div>
<script>
jQuery(function($){
$('#myblock').on('click', 'div', function () {
$(this).addClass('active').siblings().removeClass('active');
});
});
</script>
</body>