自适应高度

$(function(){
    $('.carousel ul').anoSlide({
        items: 1,
        speed: 500,
        prev: 'a.prev',
        next: 'a.next',
        auto: 3000
    });
});

<div class="carousel">
    <a class="prev"></a>
    <ul>
        <li><a href="javascript:"><img src="images/900x300.png"></a></li>
        <li><a href="javascript:"><img src="images/900x500.png"></a></li>
        <li><a href="javascript:"><img src="images/900x200.png"></a></li>
        <li><a href="javascript:"><img src="images/900x400.png"></a></li>
    </ul>
    <a class="next"></a>
</div>