图片轮播下获取鼠标点了哪个按钮

<div class="num_btn">

 <a href="javascript:void(0)">1</a>

 <a href="javascript:void(0)">2</a>

 <a href="javascript:void(0)">3</a>

 <a href="javascript:void(0)">4</a>

 <a href="javascript:void(0)">5</a>

</divl>

js:

  var aA = $(".num_btn a");

var iNow = 0;

aA.live("click",function(){

    iNow = aA.index($(this));

//如果此时鼠标点击第三个a则此时的iNow = 2；

});