Jquery 实现动态的条形统计图

页面布局如下:
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <style type="text/css">
        *
        {
            margin: 0 0 0 0;
            padding: 0 0 0 0;
        }
        .container
        {
             300;
            height: 300;
            margin: 50 0 0 50;
            border: 1px solid green;
            float: left;
            background-image: url('/images/mubk.jpg');
        }
        .control
        {
             280;
            height: 80;
            float: left;
            margin: 50 0 0 10;
            border: 1 solid #000000;
        }
        .item
        {
            height: 98%;
             30px;
            border: 1 sollid green;
            background-color: #191970;
            display: inline-block;
            display: inline;
            margin-left: 10px;
            margin-top: 10px;
            text-align: center;
        }
    </style>
    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
    <script type="text/javascript">

        $(function () {
            var timer1;
            $("#slide>div:odd").css({ 'background-color': '#308014' });
            $("#slide>div:even").css({ 'background-color': '#4169e1' });
            $("#bnt2").click(function () {
                timer1 = setInterval(initDance, 500);
            });
            $("#btn1").click(function () {
                timer1 && clearInterval(timer1);
            });

        });

        function initDance() {

            var height = parseInt(280 * Math.random()) + 5;
            var box = parseInt(7 * Math.random());
            dance(box, height);
        }

        function dance(box, height) {
            if (height) {
                $(".item").eq(box).css({ height: height });
                var obj = {};
                obj["box"] = box;
                obj["height"] = height;
                return obj;
            } else {
                return {};
            }
        }
    </script>
</head>
<body>
    <div id="slide" class="container">
        <div class="item">
            1
        </div>
        <div class="item">
            2
        </div>
        <div class="item">
            3
        </div>
        <div class="item">
            4
        </div>
        <div class="item">
            5
        </div>
        <div class="item">
            6
        </div>
        <div class="item">
            7
        </div>
        <div class="item" style=" 1; border: 0; background-color: White">
        </div>
    </div>
    <div class="control">
        <p style="display: none; position: relative">
            这是一个段落标记</p>
        <input type="button" value="停下来" id="btn1" />
        <input type="button" value="跳起来" id="bnt2" />
    </div>
</body>
</html>
运行效果图:
点击跳起来按钮效果: