RegisterFormButtonClickEvent

// Register form
private void btnRegisterRegister_Click(object sender, EventArgs e)
        {
            if (txtBoxNameRegister.Text != "" && txtBoxTelRegister.Text != "" &&
                txtBoxPasswordRegister.Text != "" && txtBoxPassCheckRegister.Text != "" &&
                txtBoxEmailRegister.Text != "" && txtBoxAddressRegister.Text != "")
            {
                if ((txtBoxPasswordRegister.Text).Equals(txtBoxPassCheckRegister.Text))
                {
                    SqlConnection sqlConn = new SqlConnection(@"Data Source=HRISI-PC;Initial Catalog=CourseWorkVP;Integrated Security=True");
                    sqlConn.Open();
                    SqlCommand sqlComm = new SqlCommand("INSERT INTO Clients(Name, Telephone, Address, Email, Password) VALUES('" + txtBoxNameRegister.Text + "', '" +
                    txtBoxTelRegister.Text + "', '" + txtBoxAddressRegister.Text + "', '" + txtBoxEmailRegister.Text + "', '" + txtBoxPasswordRegister.Text + "');", sqlConn);
                    object obj = sqlComm.ExecuteNonQuery();
                    MessageBox.Show("The user \"" + txtBoxNameRegister.Text + "\" has been sucessfully registered!");
                    sqlConn.Close();
                }
                else
                {
                    MessageBox.Show("The password didn't match!");
                }
            }
            else
            {
                MessageBox.Show("Please fill in all the fields!");
            }
        }