AmCharts错误：未捕获TypeError：无法读取属性＆＃39;图表＆＃39;未定义的

Question

这是我关于stackoverflow的第一个问题。

我正在尝试通过onclick事件渲染序列图表。 （请参阅JSfiddle - http://jsfiddle.net/w408kcmp/）。

JS：

var expIConfig;
var expIData = [{
    "period": "Week 1",
        "inflows": 5,
        "outflows": 10
}];

expIConfig = {
    "type": "serial",
        "theme": "none",
        "dataProvider": expIData,
        "startDuration": 1,
        "colors": ['#77ED84', '#FA6F0C'],
        "graphs": [{
        "balloonText": "Inflows during [[category]]: <b>[[value]]</b>",
            "fillAlphas": 0.9,
            "lineAlpha": 0.2,
            "title": "Inflows",
            "type": "column",
            "valueField": "inflows"
    }, {
        "balloonText": "Outflows during [[category]]: <b>[[value]]</b>",
            "fillAlphas": 0.9,
            "lineAlpha": 0.2,
            "title": "Outflows",
            "type": "column",
            "clustered": false,
            "columnWidth": 0.5,
            "valueField": "outflows"
    }],
        "plotAreaFillAlphas": 0.1,
        "categoryField": "period",
        "categoryAxis": {
        "gridPosition": "start",
            "labelRotation": 25
    }
};

function renderChart() {
    expIConfig.dataProvider = expIData;
    expIChart = AmCharts.makeChart("chartdiv1", expIConfig, expIData);
}

HTML：

<button onclick="renderChart()">Render</button>
<div id="chartdiv1" style="width:300px;height:325px;"></div>

资源：

<script type="text/javascript" src="http://www.amcharts.com/lib/3/amcharts.js"></script>
<script type="text/javascript" src="http://www.amcharts.com/lib/3/serial.js"></script>
<script type="text/javascript" src="http://www.amcharts.com/lib/3/themes/none.js"></script>

我收到了上述错误。有类似问题的其他人（不是amCharts相关表明它可能是由于在serial.js之后加载amcharts.js，但是，我的脚本按指定的顺序加载：amcharts.js - ＆gt; serial.js - ＆gt; none.js.

非常感谢任何帮助。

非常感谢。