使用echarts作图不能显示，网页也没报错?报错

大家帮我看一下为什么网页内容不能显示出来，也不报错，谢谢

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>ECharts</title>
    
    
    <script src="./js/esl.js"></script>


</head>

<body>
    
    
    <div id="main" style="height:500px;border:1px solid #ccc;padding:10px;"></div>

    <script type="text/javascript">
    // Step:3 conifg ECharts's path, link to echarts.js from current page.
    // Step:3 为模块加载器配置echarts的路径，从当前页面链接到echarts.js，定义所需图表路径
    require.config({
        paths:{
            echarts:'./build/echarts',
            'echarts/chart/force' : './build/echarts'

        }
    });

    // Step:4 require echarts and use it in the callback.
    // Step:4 动态加载echarts然后在回调函数中开始使用，注意保持按需加载结构定义图表路径
    require(
        [
            'echarts',
            'echarts/chart/force'

        ],
        function(ec) {
            var myChart = ec.init(document.getElementById('main'));
            var option = {
                title : {
        text: '人物关系：乔布斯',
        subtext: '数据来自人立方',
        x:'right',
        y:'bottom'
    },
    tooltip : {
        trigger: 'item',
        formatter: '{a} : {b}'
    },
    legend: {
        x: 'left',
        data:['家人','朋友']
    },
    series : [
        {
            type:'force',
            name : "人物关系",
            categories : [
                {
                    name: '人物',
                    itemStyle: {
                        normal: {
                            color : '#ff7f50'
                        }
                    }
                },
                {
                    name: '家人',
                    itemStyle: {
                        normal: {
                            color : '#87cdfa'
                        }
                    }
                },
                {
                    name:'朋友',
                    itemStyle: {
                        normal: {
                            color : '#9acd32'
                        }
                    }
                }
            ],
            itemStyle: {
                normal: {
                    label: {
                        show: true,
                        textStyle: {
                            color: '#800080'
                        }
                    },
                    nodeStyle : {
                        brushType : 'both',
                        strokeColor : 'rgba(255,215,0,0.4)',
                        lineWidth : 1
                    }
                },
                emphasis: {
                    label: {
                        show: false
                        // textStyle: null      // 默认使用全局文本样式，详见TEXTSTYLE
                    },
                    nodeStyle : {
                        //r: 30
                    },
                    linkStyle : {}
                }
            },
            minRadius : 15,
            maxRadius : 25,
            density : 0.05,
            attractiveness: 1.2,
            linkSymbol: 'arrow',
            nodes:[
                {category:0, name: '乔布斯', value : 10},
                {category:1, name: '丽萨-乔布斯',value : 2},
                {category:1, name: '保罗-乔布斯',value : 3},
                {category:1, name: '克拉拉-乔布斯',value : 3},
                {category:1, name: '劳伦-鲍威尔',value : 7},
                {category:2, name: '史蒂夫-沃兹尼艾克',value : 5},
                {category:2, name: '奥巴马',value : 8},
                {category:2, name: '比尔-盖茨',value : 9},
                {category:2, name: '乔纳森-艾夫',value : 4},
                {category:2, name: '蒂姆-库克',value : 4},
                {category:2, name: '龙-韦恩',value : 1},
            ],
            links : [
                {source : 1, target : 0, weight : 1},
                {source : 2, target : 0, weight : 2},
                {source : 3, target : 0, weight : 1},
                {source : 4, target : 0, weight : 2},
                {source : 5, target : 0, weight : 3},
                {source : 6, target : 0, weight : 6},
                {source : 7, target : 0, weight : 6},
                {source : 8, target : 0, weight : 1},
                {source : 9, target : 0, weight : 1},
                {source : 10, target : 0, weight : 1},
                {source : 3, target : 2, weight : 1},
                {source : 6, target : 2, weight : 1},
                {source : 6, target : 3, weight : 1},
                {source : 6, target : 4, weight : 1},
                {source : 6, target : 5, weight : 1},
                {source : 7, target : 6, weight : 6},
                {source : 7, target : 3, weight : 1},
                {source : 9, target : 6, weight : 1}
            ]
        }
    ]
};
var ecConfig = require('echarts/config');
function focus(param) {
    var data = param.data;
    var links = option.series[0].links;
    var nodes = option.series[0].nodes;
    if (
        data.source !== undefined
        && data.target !== undefined
    ) { //点击的是边
        var sourceNode = nodes[data.source];
        var targetNode = nodes[data.target];
        console.log("选中了边 " + sourceNode.name + ' -> ' + targetNode.name + ' (' + data.weight + ')');
    } else { // 点击的是点
        console.log("选中了" + data.name + '(' + data.value + ')');
    }
    console.log(param);