/// <summary>
        /// Adds new book into the database.
        /// </summary>
        /// <param name="sender">Contains a reference to the control that raised the event.</param>
        /// <param name="e">Contains the event data.</param>
        private void buttonSave_Click(object sender, EventArgs e)
        {
            foreach (Control c in this.Controls)
            {
                if (c is TextBox)
                {
                    TextBox textBox = c as TextBox;
                    if (textBox.Text == string.Empty)
                    {
                        MessageBox.Show("Fields can't be empty");
                        return;
                    }
                }
            }

            int   parsedValue;
            float parsedValue2;

            if (!int.TryParse(textBoxQuantity.Text, out parsedValue) || !float.TryParse(textBoxPrice.Text, out parsedValue2) || float.Parse(textBoxPrice.Text) <= 0 || int.Parse(textBoxQuantity.Text) <= 0)
            {
                MessageBox.Show("Quantity and Price are positive numbers!!!", "Warning");
                return;
            }

            else
            {
                string BookTitle    = textBoxTitle.Text;
                string Author       = textBoxAuthor.Text;
                int    Quantity     = int.Parse(textBoxQuantity.Text);
                string Publisher    = textBoxPublisher.Text;
                float  CostPrice    = float.Parse(textBoxPrice.Text);
                float  SellingPrice = CostPrice + 7;
                string ComboBoxTxt  = comboBoxGenres.Text;

                if (comboBoxGenres.Text == "")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 101);
                }
                else if (comboBoxGenres.Text == "Action")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 102);
                }
                else if (comboBoxGenres.Text == "Adventure")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 103);
                }
                else if (comboBoxGenres.Text == "Crime")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 104);
                }
                else if (comboBoxGenres.Text == "Drama")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 105);
                }
                else if (comboBoxGenres.Text == "Fantasy")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 106);
                }
                else if (comboBoxGenres.Text == "Horror")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 107);
                }
                else if (comboBoxGenres.Text == "Thriller")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 108);
                }
                else if (comboBoxGenres.Text == "Science Fiction")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 109);
                }
                else if (comboBoxGenres.Text == "Guide")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 110);
                }
                else if (comboBoxGenres.Text == "Health")
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 111);
                }
                else
                {
                    business.AddBook(BookTitle, Author, Publisher, Quantity, CostPrice, SellingPrice, 112);
                }

                MessageBox.Show("Successfully Added", "Success");

                this.Close();
            }
        }