diff --git a/src/components/app/app.ts b/src/components/app/app.ts
index ae3098d..0640836 100644
--- a/src/components/app/app.ts
+++ b/src/components/app/app.ts
@@ -12,7 +12,7 @@ export default class App extends Vue
 
     public courses = null;
 
-    public selectedTab: string = "";
+    public selectedTab: string = "overall";
 
     /**
      * This is called when the user logs in.
diff --git a/src/pages/overall/graph-overall/graph-overall.ts b/src/pages/overall/graph-overall/graph-overall.ts
index c1b3baf..8fff5cf 100644
--- a/src/pages/overall/graph-overall/graph-overall.ts
+++ b/src/pages/overall/graph-overall/graph-overall.ts
@@ -4,7 +4,8 @@ import {Component, Vue} from 'vue-property-decorator';
 })
 export default class GraphOverall extends Vue
 {
-    public chartData = {
+    public chartData =
+    {
         columns: ['日期', '访问用户', '下单用户', '下单率'],
         rows: [
             { '日期': '1/1', '访问用户': 1393, '下单用户': 1093, '下单率': 0.32 },
diff --git a/src/pages/overall/graph-overall/graph-overall.vue b/src/pages/overall/graph-overall/graph-overall.vue
index 1ff19db..c2f0974 100644
--- a/src/pages/overall/graph-overall/graph-overall.vue
+++ b/src/pages/overall/graph-overall/graph-overall.vue
@@ -1,6 +1,6 @@
 <template>
     <div id="graph-overall">
-        <ve-line :data="chartData"></ve-line>
+        <ve-line :data="chartData" :extend="{series: {smooth: false}}"></ve-line>
     </div>
 </template>