private void lendBookToolStripMenuItem1_Click(object sender, EventArgs e)
        {
            Window_Popup_LendBook w = new Window_Popup_LendBook();

            w.setMainWindowRefrence(this);
            w.ShowDialog();
        }
        private void dgvListOfCopies_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            DataGridView dgv = sender as DataGridView;

            if (dgv == null)
            {
                return;
            }

            if (dgv.CurrentRow.Selected)
            {
                int _book_id = Convert.ToInt32(dgv.SelectedRows[0].Cells["Book ID"].Value);

                Book _book = EntityBroker.getBookByBookID(_book_id);

                if (_book.BookStatus == 1)
                {
                    try
                    {
                        Window_Popup_LendBook w = new Window_Popup_LendBook(_book_id);
                        w.setMainWindowRefrence(MainWindowObject);
                        w.ShowDialog();
                        winObj.Close();
                    }
                    catch {
                        MessageBox.Show("Please close the window manually");
                    }
                }
                else
                {
                    Window_Popup_ReturnBook w = new Window_Popup_ReturnBook(_book_id);
                    w.setMainWindowRefrence(MainWindowObject);
                    w.ShowDialog();
                    winObj.Close();
                }
            }
        }
        private void btnSearchByBookID_Click(object sender, EventArgs e)
        {
            int _book_id = 0;

            try
            {
                _book_id = Convert.ToInt32(txtSearchByBookID.Text);
            }
            catch {
                MessageBox.Show("Book ID you entered is not valid type.");
                return;
            }

            Book _book = new Book();

            _book = EntityBroker.getBookByBookID(_book_id);

            if (_book == null)
            {
                MessageBox.Show("Book ID you entered is not in the library.");
                return;
            }

            if (_book.BookStatus == 1)
            {
                Window_Popup_LendBook w = new Window_Popup_LendBook(_book_id);
                w.setMainWindowRefrence(MainWindowObject);
                w.ShowDialog();
            }
            else if (_book.BookStatus == 0)
            {
                Window_Popup_ReturnBook w = new Window_Popup_ReturnBook(_book_id);
                w.setMainWindowRefrence(MainWindowObject);
                w.ShowDialog();
            }
        }