//end of menu events

        //add book
        private void btn_add_Click(object sender, EventArgs e)
        {
            if (tb_name.Text == "" || tb_publisher.Text == "" || tb_price.Text == "" || tb_quantity.Text == "")
            {
                MessageBox.Show("All fields are mandatory");
            }
            else
            {
                try
                {
                    con = DatabaseConnection.connectDB();
                    con.Open();
                    SqlCommand cmd    = new SqlCommand("Insert into book values('" + tb_bookId.Text + "','" + tb_name.Text + "','" + cb_edition.Text + "','" + tb_publisher.Text + "','" + date_of_purchase.Text + "','" + tb_price.Text + "','" + tb_quantity.Text + "','" + tb_quantity.Text + "')", con);
                    int        result = cmd.ExecuteNonQuery();
                    if (result == 1)
                    {
                        MessageBox.Show("New Book Added!!");
                        tb_bookId.Text         = Increment.bookIncrement().ToString();
                        tb_name.Text           = "";
                        cb_edition.Text        = "1";
                        tb_publisher.Text      = "";
                        tb_price.Text          = "";
                        tb_quantity.Text       = "";
                        date_of_purchase.Value = DateTime.Today;
                    }
                    else
                    {
                        MessageBox.Show("Something Went Wrong!!");
                    }
                    con.Close();
                }
                catch (SqlException ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }
 //Page Load
 private void NewBook_Load(object sender, EventArgs e)
 {
     menu_user.Text = "";
     menu_user.Text = global.user;
     tb_bookId.Text = Increment.bookIncrement().ToString();
 }