private void UpdateBook_Load(object sender, EventArgs e)
        {
            txtISBN.Text     = book.ISBN;
            txtName.Text     = book.Name;
            txtPrice.Text    = book.Price.ToString();
            txtQuantity.Text = book.Quantity.ToString();
            txtDesc.Text     = book.Description;
            txtPrice.Text    = book.Price.ToString();
            txtStatus.Text   = book.Status;


            for (int i = 0; i < ListAuthors.Items.Count; i++)
            {
                int count = 0;
                for (int t = count; t < book.Author.Count; t++)
                {
                    if (book.Author[t].ID == ((AuthorData)ListAuthors.Items[i]).ID)
                    {
                        ListAuthors.SetSelected(i, true);
                        count = t;
                        break;
                    }
                }
            }

            for (int i = 0; i < ListCategory.Items.Count; i++)
            {
                for (int t = 0; t < book.Category.Count; t++)
                {
                    if (((CategoryData)ListCategory.Items[i]).ID == book.Category[t].ID)
                    {
                        ListCategory.SetSelected(i, true);
                        break;
                    }
                }
            }
            for (int i = 0; i < cboPublisher.Items.Count; i++)
            {
                if (book.Publisher_ID == ((PublisherData)cboPublisher.Items[i]).ID)
                {
                    cboPublisher.SelectedIndex = i;
                }
            }
        }