diff --git a/chapter2/mysite/myapp/static/scripts/trend.js b/chapter2/mysite/myapp/static/scripts/trend.js
index 4145c0f..7146163 100755
--- a/chapter2/mysite/myapp/static/scripts/trend.js
+++ b/chapter2/mysite/myapp/static/scripts/trend.js
@@ -12,7 +12,8 @@ $(function(){
 
    var myColor = ['#1089E7', '#F57474', '#56D0E3', '#F8B448', '#8B78F6'];
 
-   var histogramChart1 = echarts.init(document.getElementById('histogramChart1'));
+   if(document.getElementById('histogramChart1')){
+      var histogramChart1 = echarts.init(document.getElementById('histogramChart1'));
    if(histogramChart1){
     histogramChart1.setOption({
 
@@ -77,6 +78,8 @@ $(function(){
      ]
    })
    }
+   }
+   
    
 
    //主要症状
@@ -143,7 +146,8 @@ $(function(){
    })
 
    //传染病发病趋势
-   var lineChart1 = echarts.init(document.getElementById('lineChart1'));
+   if (document.getElementById('lineChart1')) {
+    var lineChart1 = echarts.init(document.getElementById('lineChart1'));
    if(lineChart1){
     lineChart1.setOption({
      title: {
@@ -224,6 +228,8 @@ $(function(){
 
    })
    }
+   }
+   
    
 
    //TOP10销量趋势