diff --git a/app.js b/app.js
index 4b6378f..3bcd823 100644
--- a/app.js
+++ b/app.js
@@ -7,6 +7,11 @@ addForm.addEventListener("submit", addBook);
 
 let bookTable = document.getElementById("bookTableBody");
 
+let lastBookId = 0;
+function genBookId() {
+    return lastBookId++;
+}
+
 function addBook(event){
     event.preventDefault();
     console.log("Add Book", event.target.bookTitle.value);