diff --git a/fortune_generator/index.html b/fortune_generator/index.html
index d5c8afb..add8cfd 100644
--- a/fortune_generator/index.html
+++ b/fortune_generator/index.html
@@ -53,7 +53,7 @@
         </div>
       </div>
     </div>
-    <button onclick="getLuck()">點擊打卡</button>
+    <button id="btn" onclick="getLuck()">點擊打卡</button>
   </div>
   <canvas id="Matrix"></canvas>
   <script src="./fortune.js"></script>