private void btnSave_Click(object sender, EventArgs e)
        {
            if (txtAddress.Text == "" || txtEmail.Text == "" || txtName.Text == "" || txtPassword.Text == "" || txtPhone.Text == "" || txtUsername.Text == "")
            {
                MessageBox.Show("Please fill in all fields!");
            }
            else if (rbFemale.Checked == false && rbMale.Checked == false)
            {
                MessageBox.Show("Please choose your gender!");
            }
            else if (boxFav.SelectedIndex == -1 || boxFav.SelectedItem == "")
            {
                MessageBox.Show("Please choose your job!");
            }
            else if (txtPassword.TextLength < 6)
            {
                MessageBox.Show("Password must be more than 6 characters!");
            }
            else
            {
                try
                {
                    String gender;
                    if (rbFemale.Checked)
                    {
                        gender = "Female";
                    }
                    else
                    {
                        gender = "Male";
                    }

                    int    id     = Int32.Parse(getLastID().Substring(3)) + 1;
                    String custid = "CST" + id.ToString().PadLeft(5, '0');

                    var data = new Customer
                    {
                        Customer_ID      = custid,
                        Customer_Name    = txtName.Text,
                        Customer_Address = txtAddress.Text,
                        Preffered_Genre  = boxFav.Text,
                        Birth_Date       = birthDatePicker.Value,
                        Phone_Number     = txtPhone.Text,
                        Username         = txtUsername.Text,
                        Password         = txtPassword.Text,
                        Email            = txtEmail.Text,
                        Gender           = gender,
                        Status           = "NOT VERIFIED",
                        Balance          = 0
                    };
                    ent.Customers.Add(data);
                    VerifyCode verify = new VerifyCode();
                    ent.SaveChanges();
                    MessageBox.Show("Please verify your account to log-in");
                    this.Hide();
                    loginForm.Show();
                }
                catch
                {
                    MessageBox.Show("Username or email has been used!");
                }
            }
        }
        private void button2_Click(object sender, EventArgs e)
        {
            VerifyCode verify = new VerifyCode();

            verify.Show();
        }