不知道这样行不行..

<script type="text/javascript">
        $(function () {
            $("span").animate({
                width: "80px",
                height: "80px"
            },
            3000, function () {
                $("#tip").html("执行完成!");
                $("span").html("点击缩小!");
            });
            
            $("span").bind("click",function(){
                $("span").animate({width:"0px",height:"0px"},3000,function(){
                  $("#tip").html("已经还原!");
                });
            })
        });
    </script>