/// <summary>
        /// 사원 정보 입력란에서 확인 버튼 클릭 시
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btn_OkJoin_Click(object sender, EventArgs e)
        {
            if (tb_EmployeeName.Text != "" && tb_EmployeeNum.Text != "" && tb_Birth.Text != "" && tb_Gender.Text != "")
            {
                avr_SerialPort.Close();
                manage_state = true;
                RFID_Tag_Page dlgRFID = new RFID_Tag_Page(this);
                dlgRFID.ShowDialog(this);
                avr_SerialPort.Open();

                if (dlgRFID.DialogResult == DialogResult.OK)
                {
                    conn = new MySqlConnection(strConn);
                    conn.Open();
                    cmd = new MySqlCommand("", conn);
                    string gender = "";

                    if (tb_Gender.Text == "1" || tb_Gender.Text == "3")
                    {
                        gender = "M";
                    }
                    else if (tb_Gender.Text == "2" || tb_Gender.Text == "4")
                    {
                        gender = "W";
                    }

                    sql             = "INSERT INTO employee_info (rfid_num, emp_num, emp_name, emp_gender, emp_birth) VALUES ('";
                    sql            += rfid + "', '" + tb_EmployeeNum.Text + "', '" + tb_EmployeeName.Text + "', '" + gender + "', '" + tb_Birth.Text + "')";
                    cmd.CommandText = sql;
                    cmd.ExecuteNonQuery();

                    tb_EmployeeNum.Text = ""; tb_EmployeeName.Text = ""; tb_Gender.Text = ""; tb_Birth.Text = "";
                    rb_State.Text       = "사원 정보가 정상적으로 등록되었습니다.";
                }
            }
            else
            {
                MessageBox.Show("사원 정보를 모두 입력해주세요.");
            }
        }
        /// <summary>
        /// 사원 정보 삭제란에서 확인 버튼 클릭 시
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btn_OkDel_Click(object sender, EventArgs e)
        {
            if (tb_EmployeeNameDel.Text != "" && tb_EmployeeNumDel.Text != "" && tb_BirthDel.Text != "" && tb_GenderDel.Text != "")
            {
                avr_SerialPort.Close();
                manage_state = false;
                RFID_Tag_Page dlgRFID = new RFID_Tag_Page(this);
                dlgRFID.ShowDialog(this);
                avr_SerialPort.Open();

                if (dlgRFID.DialogResult == DialogResult.OK)
                {
                    conn = new MySqlConnection(strConn);
                    conn.Open();
                    cmd = new MySqlCommand("", conn);
                    string gender     = "";
                    bool   info_match = false;

                    if (tb_GenderDel.Text == "1" || tb_GenderDel.Text == "3")
                    {
                        gender = "M";
                    }
                    else if (tb_GenderDel.Text == "2" || tb_GenderDel.Text == "4")
                    {
                        gender = "W";
                    }

                    sql             = "SELECT * FROM employee_info WHERE rfid_num='";
                    sql            += rfid + "'";
                    cmd.CommandText = sql;
                    reader          = cmd.ExecuteReader();

                    while (reader.Read())
                    {
                        if (tb_EmployeeNumDel.Text == reader["emp_num"].ToString() &&
                            tb_EmployeeNameDel.Text == reader["emp_name"].ToString() &&
                            gender == reader["emp_gender"].ToString() &&
                            tb_BirthDel.Text == reader["emp_birth"].ToString())
                        {
                            info_match = true;
                        }
                    }
                    reader.Close();

                    if (info_match == true)
                    {
                        sql             = "DELETE FROM employee_info WHERE rfid_num='";
                        sql            += rfid + "'";
                        cmd.CommandText = sql;
                        cmd.ExecuteNonQuery();

                        tb_EmployeeNumDel.Text = ""; tb_EmployeeNameDel.Text = ""; tb_GenderDel.Text = ""; tb_BirthDel.Text = "";
                        rb_State.Text          = "사원 정보가 정상적으로 삭제되었습니다.";
                        info_match             = false;
                    }
                    else
                    {
                        MessageBox.Show("입력하신 사원 정보와 rfid카드의 정보가 서로 다릅니다. \n 다시 입력해주세요.");
                    }
                }
            }
            else
            {
                MessageBox.Show("사원 정보를 모두 입력해주세요.");
            }
        }