HTML

<ul class="introduce">
    <li class="brand" navindex="0"><a href="http://sucaihuo.com/" target="_blank"><img src="images/lnb110_off.png" alt=""></a></li>
    <li class="program"  navindex="1"><a href="http://sucaihuo.com/" target="_blank"><img src="images/lnb120_on.png" alt=""></a></li>
    <li class="curriculum"  navindex="2"><a href="http://sucaihuo.com/" target="_blank"><img src="images/lnb130_off.png" alt=""></a></li>
    <li class="study_effect"  navindex="3"><a href="http://sucaihuo.com/" target="_blank"><img src="images/lnb140_off.png" alt=""></a></li>
    <li class="character"  navindex="4"><a href="http://sucaihuo.com/" target="_blank"><img src="images/lnb150_off.png" alt=""></a></li>
    <li class="online_study last"  navindex="5"><a href="http://sucaihuo.com/" target="_blank"><img src="images/lnb160_off.png" alt=""></a></li>
</ul>

menu.js

$(".introduce li").mouseover(function() {
    var index = $(this).attr('navindex');
    var targetTop = 95 + index * 29;
    highlight(index);
    start_move(depth2_bg, targetTop);
});

// recover
$("#navigation").mouseout(function() {
    highlight(1);
    start_move(depth2_bg, oldTop);
});