鼠标指中图片切换 hover

//HTML 代码        

          <div class="img_big">
                        <img src="大图片地址" />//大图
                    </div>
                    <div class="img_small">
                        <ul>//小图片排列
                            <li>
                                <a data-url="小图片地址">
                                    <img src="小图片地址" />
                                </a>
                            </li>
                        </ul>
                    </div>

//JS 代码

<script type="text/javascript">

    $(".img_small li a").hover(function () {
        $(".img_big img").attr("src", $(this).data("url"));
    });
</script>