echart不报错却不显示是为什么？

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="echart text.aspx.cs" Inherits="echart_text" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>    
    </div>
    </form>
    <div id="main" style=" height:300px; width:600px "></div>
    <script src="echarts/dist/echarts-all.js"></script>
    <script type="text/javascript">
        var myChart = echarts.init(document.getElementById("main"));
        var option ={
        title:{text:'平均成绩',x:'center'},
        tooltip:{},
        legend:{orient:'vertical',x:'left',data:['平均分']},
        xAxis:{data:["c001","c002","c003","c007"]},
        yAxis:{},
        series:[{
        name:'平均分'，
        type:'bar',
        data:[70,85,34,22]
        }]
        }
        myChart.setOption(option);
        </script>
</body>
</html>

 

注意echarts.js是否成功导入 24行平均分后的逗号是中文逗号改成英文

好像要给div设置宽高才可以