diff --git a/hello/app.js b/hello/app.js
index 26109ec..7d9c1f2 100644
--- a/hello/app.js
+++ b/hello/app.js
@@ -3,6 +3,7 @@
 let bookId = 0;
 
 function genNewBookId() {
+    bookID = 1
     bookID++;
     return bookId;
 }