给一个ul列表中点击到的li赋予样式，并移除兄弟节点的此样式

<div class="list-group" id="myList">
	<a href="#" class="list-group-item list-group-item-action" id = "letActive"> Cras justo odio </a>
	<a href="#" class="list-group-item list-group-item-action active">Dapibus ac facilisis in</a>
	<a href="#" class="list-group-item list-group-item-action">Morbi leo risus</a>
	<a href="#" class="list-group-item list-group-item-action">Porta ac consectetur ac</a>
	<a href="#" class="list-group-item list-group-item-action " >Vestibulum at eros</a>
</div>

$(".list-group-item").click(function () {
	$(".list-group-item").siblings("a").removeClass("active");
	$(this).addClass("active");
});