diff --git a/app.js b/app.js
index b131860..4023cfa 100644
--- a/app.js
+++ b/app.js
@@ -1,80 +1,85 @@
-document.addEventListener('DOMContentLoaded', function(){
+document.addEventListener('DOMContentLoaded', function () {
+    const list = document.querySelector('#book-list ul');
+    //delete books
+    list.addEventListener('click', function (e) {
+        if (e.target.className == 'delete') {
+            const li = e.target.parentElement;
+            list.removeChild(li);
 
-  const list = document.querySelector('#book-list ul');
-  const forms = document.forms;
+        }
+    })
+
+    //add books
+    const addForm = document.forms['add-book'];
 
-  // delete books
-  list.addEventListener('click', (e) => {
-    if(e.target.className == 'delete'){
-      const li = e.target.parentElement;
-      li.parentNode.removeChild(li);
-    }
-  });
+    addForm.addEventListener('submit', function (e) {
+        e.preventDefault();
+        var value = addForm.querySelector('input[type="text"]').value;
 
-  // add books
-  const addForm = forms['add-book'];
-  addForm.addEventListener('submit', function(e){
-    e.preventDefault();
 
-    // create elements
-    const value = addForm.querySelector('input[type="text"]').value;
-    const li = document.createElement('li');
-    const bookName = document.createElement('span');
-    const deleteBtn = document.createElement('span');
 
-    // add text content
-    bookName.textContent = value;
-    deleteBtn.textContent = 'delete';
+        //create elements
+        const li = document.createElement('li');
+        const bookName = document.createElement('Span');
+        const deleteBtn = document.createElement('span');
 
-    // add classes
-    bookName.classList.add('name');
-    deleteBtn.classList.add('delete');
+        //add content
+        if (value == "") {
+            alert('Please Enter a book title');
+        } else {
+            deleteBtn.textContent = 'delete';
+            bookName.textContent = value;
 
-    // append to DOM
-    li.appendChild(bookName);
-    li.appendChild(deleteBtn);
-    list.appendChild(li);
-  });
+            //add classes
+            bookName.classList.add('name')
+            deleteBtn.classList.add('delete')
 
-  // hide books
-  const hideBox = document.querySelector('#hide');
-  hideBox.addEventListener('change', function(e){
-    if(hideBox.checked){
-      list.style.display = "none";
-    } else {
-      list.style.display = "initial";
-    }
-  });
+            //append to document
+            li.appendChild(bookName);
+            li.appendChild(deleteBtn);
+            list.appendChild(li);
+        }
+        addForm.querySelector('input[type="text"]').value = "";
+    })
 
-  // filter books
-  const searchBar = forms['search-books'].querySelector('input');
-  searchBar.addEventListener('keyup', (e) => {
-    const term = e.target.value.toLowerCase();
-    const books = list.getElementsByTagName('li');
-    Array.from(books).forEach((book) => {
-      const title = book.firstElementChild.textContent;
-      if(title.toLowerCase().indexOf(e.target.value) != -1){
-        book.style.display = 'block';
-      } else {
-        book.style.display = 'none';
-      }
-    });
-  });
+    //hide books
+    const hideBox = document.querySelector('#hide');
 
-  // tabbed content
-  const tabs = document.querySelector('.tabs');
-  const panels = document.querySelectorAll('.panel');
-  tabs.addEventListener('click', (e) => {
-    if(e.target.tagName == 'LI'){
-      const targetPanel = document.querySelector(e.target.dataset.target);
-      Array.from(panels).forEach((panel) => {
-        if(panel == targetPanel){
-          panel.classList.add('active');
-        }else{
-          panel.classList.remove('active');
+    hideBox.addEventListener('change', function (e) {
+        if (hideBox.checked) {
+            list.style.display = "none";
+        } else {
+            list.style.display = 'block';
         }
-      });
-    }
-  });
+    })
+    //filter books
+    const searchBar = document.forms['search-books'].querySelector('input');
+    searchBar.addEventListener('keyup', function (e) {
+        const term = e.target.value.toLowerCase();
+        const books = list.getElementsByTagName('li');
+        Array.from(books).forEach(function (book) {
+            const title = book.firstElementChild.textContent;
+            if (title.toLowerCase().indexOf(term) != -1) {
+                book.style.display = 'block';
+            } else {
+                book.style.display = 'none';
+            }
+        })
+    })
+    // tabbed content
+    const tabs = document.querySelector('.tabs');
+    const panels = document.querySelectorAll('.panel');
 
+    tabs.addEventListener('click', function (e) {
+        if (e.target.tagName == "LI") {
+            const targetPanel = document.querySelector(e.target.dataset.target);
+            panels.forEach(function (panel) {
+                if (panel == targetPanel) {
+                    panel.classList.add('active');
+                } else {
+                    panel.classList.remove('active');
+                }
+            })
+        }
+    })
 })