为什么没有选中效果？


<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js"></script>
</head><body>
<div class="aaa"><a href="javascript:void(0)"><img src="images/ad1.png" width="468" height="60"></a></div>
<div class="aaa"><a href="javascript:void(0)"><img src="images/ad1.png" width="468" height="60"></a></div><style type="text/css">
*{margin:0; padding:0}
.aaa a{cursor:default;}
.aaa img {border:1px solid #ccc; padding:2px;}
.aaa img:hover{border:1px solid #c30;}
.pick{border:1px solid #c30 !important;}
</style>
<script>
$(".aaa a").live('click',function(){
  $("aaa img").removeClass("pick");
$(this).children("img").addClass("pick");})
</script>
</body>
</html>