private void AttendenceDetail_Load(object sender, EventArgs e)
        {
            ClassAttendence classAttendence = new ClassAttendence();

            dgvClassAttendence.DataSource = classAttendence.Showdata();
            dgvClassAttendence.Columns.Add(classAttendence.Editbtn());
            dgvClassAttendence.Columns.Add(classAttendence.Deletebtn());
        }
        private void btnUpdate_Click(object sender, EventArgs e)
        {
            ClassAttendence classattend = new ClassAttendence();

            dgvClassAttendence.DataSource = classattend.Showdata();
        }