private void Bt_Remove_Click(object sender, EventArgs e)
        {
            db.closeConnection();
            db.DeleteEmp_Rate(Tb_Name.Text, RateID.ToString());

            Tb_Role.ResetText();
            Tb_Name.ResetText();
            Tb_Starttime.ResetText();
            Tb_EndTime.ResetText();
            Tb_RPH.ResetText();
            Tb_Date.ResetText();
        }
        private void Bt_Update_Click(object sender, EventArgs e)
        {
            db.closeConnection();
            //
            SqlCommand cmd = db.UpdateEmp_rate(Tb_Role.Text, Tb_Name.Text, Tb_Starttime.Text, Tb_EndTime.Text, Convert.ToDouble(Tb_RPH.Text), Tb_Date.Text, RateID.ToString());

            cmd.Parameters.AddWithValue("@Role", role);
            cmd.Parameters.AddWithValue("@Name", name);
            cmd.Parameters.AddWithValue("@StartTime", starttime);
            cmd.Parameters.AddWithValue("@EndTime", endtime);
            cmd.Parameters.AddWithValue("@RPH", RPH);
            cmd.Parameters.AddWithValue("@Date", Date);

            cmd.ExecuteNonQuery();

            Tb_Role.ResetText();
            Tb_Name.ResetText();
            Tb_Starttime.ResetText();
            Tb_EndTime.ResetText();
            Tb_RPH.ResetText();
            Tb_Date.ResetText();
        }