private void button4_Click(object sender, EventArgs e)
        {
            conn.Open();
            string           query = "insert into add_customer(customer_name,customer_email,customer_mobile,customer_address) values ('" + textBox1.Text + "','" + textBox2.Text + "','" + textBox3.Text + "','" + textBox4.Text + "')";
            MySqlDataAdapter sda   = new MySqlDataAdapter(query, conn);

            sda.SelectCommand.ExecuteNonQuery();
            conn.Close();
            MessageBox.Show("Type successfully added");
            Form10 s = new Form10();

            s.Show();
            this.Hide();
        }