diff --git a/chapter2/mysite/myapp/static/scripts/trend.js b/chapter2/mysite/myapp/static/scripts/trend.js
index 012f81b..4145c0f 100755
--- a/chapter2/mysite/myapp/static/scripts/trend.js
+++ b/chapter2/mysite/myapp/static/scripts/trend.js
@@ -13,7 +13,8 @@ $(function(){
    var myColor = ['#1089E7', '#F57474', '#56D0E3', '#F8B448', '#8B78F6'];
 
    var histogramChart1 = echarts.init(document.getElementById('histogramChart1'));
-   histogramChart1.setOption({
+   if(histogramChart1){
+    histogramChart1.setOption({
 
      color:['#5bc0de'],
      grid:{
@@ -75,6 +76,8 @@ $(function(){
          },
      ]
    })
+   }
+   
 
    //主要症状
    var histogramChart2 = echarts.init(document.getElementById('histogramChart2'));
@@ -141,7 +144,8 @@ $(function(){
 
    //传染病发病趋势
    var lineChart1 = echarts.init(document.getElementById('lineChart1'));
-   lineChart1.setOption({
+   if(lineChart1){
+    lineChart1.setOption({
      title: {
         text: '访问趋势',
         textStyle:{
@@ -219,6 +223,8 @@ $(function(){
      ]
 
    })
+   }
+   
 
    //TOP10销量趋势
    var histogramChart3_names = [];