diff --git a/app.js b/app.js
index 511bd2e..604687c 100644
--- a/app.js
+++ b/app.js
@@ -12,6 +12,8 @@ function genBookId() {
     return lastBookId++;
 }
 
+let books = {}
+
 function addBook(event){
     event.preventDefault();
     console.log("Add Book", event.target.bookTitle.value);