diff --git a/app.js b/app.js
index 187fcae..0fc837f 100644
--- a/app.js
+++ b/app.js
@@ -1,16 +1,177 @@
-const books = [
-  { author: "J.D. Salinger", title: "The Catcher in the Rye", id: 1 },
-  { author: "Harper Lee", title: "To Kill a Mockingbird", id: 2 },
-  { author: "George Orwell", title: "1984", id: 3 },
-  { author: "F. Scott Fitzgerald", title: "The Great Gatsby", id: 4 },
-  { author: "Jane Austen", title: "Pride and Prejudice", id: 5 },
+function Library(name, books)
+{
+this.name=name;
+this.books = [...books];
+this.addBook=function(title,author)
+{
+  console.log("__________ADD__________");
+  let new_book;
+  let id;
+  let status;
+  id=this.books[this.books.length-1].id+1;
+  status=new BookStatus();
+  new_book=new Book(title,author,id,status);
+  this.books.push(new_book);
+  console.log("the book ((("+new_book.title+"))) Aadded to  the library ");
+  console.log("_______________________");
+}
+this.checkOutBook = function(id, patron)
+{
+  console.log("__________CHECK OUT__________");
+  let test_id=false;
+  let test_book;
+  test_book = this.books.find(function(v){
+    return v.id == id;
+  });
+  if(test_book != undefined)
+  {
+   if(test_book.status.checkOut == false)
+   {
+     test_book.status.checkOut=true;
+     test_book.status.patron = {...patron};
+     // test_book.status.patron.id = patron.id;
+     console.log("the book ((("+test_book.title+"))) cheked out from the library , by ((("+patron.name+")))");
+    }else
+    {
+      console.log("Sooory!!! this book ((("+test_book.title+" ))) can not checked out , becuase the books is checked out");
+    }
+  }else
+  {
+    console.log("Sooory!!! the book with id : ((("+id+" ))) can not checked out , becuase the books is removed");
+  }
+  console.log("__________________________");
+}
+this.removeBook=function(id)
+{
+  console.log("__________REMOVE__________");
+  let test_book;
+  test_book=this.books.find(function(v){
+    return v.id==id;
+  });
+  if(test_book)
+  {
+    this.books = this.books.filter(function(v){
+      return v.id !== id;
+   });
+   console.log("the book ((("+test_book.title+" ))) removed from library");
+  }else
   {
-    author: "J.K. Rowling",
-    title: "Harry Potter and the Philosopher's Stone",
-    id: 6,
-  },
-  { author: "J.R.R. Tolkien", title: "The Hobbit", id: 7 },
-  { author: "George Orwell", title: "The Lord of the Rings", id: 8 },
-  { author: "Aldous Huxley", title: "Animal Farm", id: 9 },
-  { author: "Aldous Huxley", title: "Brave New World", id: 10 },
+    console.log("the book with id : ((("+id+" ))) can not removed , becuase it is unavailable");
+  }
+  console.log("__________________________");
+}
+this.checkIn=function(id)
+{
+  let test_book;
+  test_book = this.books.find(function(v){
+    return v.id==id;
+  });
+  if(test_book)
+  {
+    test_book.status.checkOut=false;
+    test_book.status.patron=null;
+    console.log("the book ((( "+test_book.title+" ))) check in to library");
+
+  }
+}
+this.getBookById=function(id)
+{
+  let test_book;
+  test_book=this.books.find(function(v){
+    return v.id == id;
+  });
+  return test_book;
+}
+this.display=function()
+{
+  console.log("__________________________DISPLAY__________________________");
+  for(let i=0;i<this.books.length;++i)
+  {
+    console.log("__________________________"+this.books[i].id+"__________________________");
+    for(let p in this.books[i])
+    {
+      if(p=="status" && this.books[i][p].patron!=null)
+      {
+        console.log("status-check out = "+this.books[i][p].checkOut);
+        console.log("status-patron = "+this.books[i][p].patron.name);
+      }else
+      {
+        console.log(p + " = "+this.books[i][p]);
+      }
+    }
+    console.log("______________________________________________________");
+  }
+  console.log("___________________________________________________________");
+}
+}
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+function Book(title, author, id, status)
+{
+this.title=title;
+this.author=author;
+this.id=id;
+this.status=status;
+}
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+function Patron(name, id)
+{
+this.name=name;
+this.id=id;
+}
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+function BookStatus(checkOut=false, patron=null)
+{
+this.checkOut=checkOut;
+this.patron=patron;
+}
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+const books = [
+  { author: "J.D. Salinger", title: "The Catcher in the Rye", id: 1,status : new BookStatus() },
+  { author: "Harper Lee", title: "To Kill a Mockingbird", id: 2 ,status : new BookStatus()},
+  { author: "George Orwell", title: "1984", id: 3,status : new BookStatus() },
+  { author: "F. Scott Fitzgerald", title: "The Great Gatsby", id: 4,status : new BookStatus() },
+  { author: "Jane Austen", title: "Pride and Prejudice", id: 5,status : new BookStatus() },
+  {author: "J.K. Rowling",title: "Harry Potter and the Philosopher's Stone",id: 6,status : new BookStatus()},
+  { author: "J.R.R. Tolkien", title: "The Hobbit", id: 7,status : new BookStatus() },
+  { author: "George Orwell", title: "The Lord of the Rings", id: 8 ,status : new BookStatus()},
+  { author: "Aldous Huxley", title: "Animal Farm", id: 9 ,status : new BookStatus()},
+  { author: "Aldous Huxley", title: "Brave New World", id: 10,status : new BookStatus() },
 ];
+
+let library1 = new Library("Abbas Alnajafy Library",books);
+let patron1 = new Patron("Abbas Abd Alhusain",1);
+let patron2 = new Patron("Patron-2",2);
+let patron3 = new Patron("Patron-3",3);
+let patron4 = new Patron("Patron-4",4);
+let patron5 = new Patron("Patron-5",5);
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+console.log(library1.books);
+library1.addBook( "Author-11" , "php and myqsl"  );
+library1.addBook( "Author-12" , "js essential" );
+library1.addBook( "Author-13" , "python language" );
+library1.addBook( "Author-14" , "python language" );
+library1.addBook( "Author-15" , "python language" );
+library1.removeBook(1);
+library1.removeBook(100);
+library1.removeBook(12);
+library1.removeBook(120);
+library1.checkOutBook(1,patron1);
+library1.checkOutBook(5,patron2);
+library1.checkOutBook(11,patron2);
+library1.checkOutBook(2,patron3);
+library1.checkOutBook(5,patron4);
+library1.checkOutBook(10,patron5);
+library1.checkIn(1);
+library1.checkIn(5);
+library1.checkIn(11);
+library1.display();