private void btnBack_Click(object sender, EventArgs e)
{
//display warning message
DialogResult result = MessageBox.Show("If you click yes, you will lost all data.", "Make sure go back.", MessageBoxButtons.YesNo);
//remove all data and go back to checklist
if (result == DialogResult.Yes)
{
DataSheet.Columns.Clear();
CheckList.Visible = true;
btnUpdate.Visible = true;
menuData.Visible = false;
layResult.Visible = false;
lblAttedence.Visible = false;
lblAttendence2.Visible = false;
txtAttedence.Visible = false;
resultAttendence.Visible = false;
resultAttendence.Text = "";
emptyAttendence.Visible = false;
lblInclass.Visible = false;
lblInclass2.Visible = false;
txtInclass.Visible = false;
resultInclass.Visible = false;
resultInclass.Text = "";
emptyInclass.Visible = false;
lblAssignment.Visible = false;
lblAssignment2.Visible = false;
txtAssignment.Visible = false;
resultAssignment.Visible = false;
resultAssignment.Text = "";
emptyAssignment.Visible = false;
lblMidterm.Visible = false;
lblMidterm2.Visible = false;
txtMidterm.Visible = false;
resultMidterm.Visible = false;
resultMidterm.Text = "";
emptyMidterm.Visible = false;
lblFinal.Visible = false;
lblFinal2.Visible = false;
txtFinal.Visible = false;
resultFinal.Visible = false;
resultFinal.Text = "";
emptyFinal.Visible = false;
lblOther.Visible = false;
lblOthers2.Visible = false;
txtOther.Visible = false;
resultOther.Visible = false;
resultOther.Text = "";
emptyOthers.Visible = false;
lblInstruction.Visible = true;
lblTotal.Visible = false;
lblTotal.Text = "";
resultTotal.Visible = false;
resultTotal.Text = "";
resultTotal2.Visible = false;
resultTotal2.Text = "";
resultTotal3.Visible = false;
resultTotal3.Text = "";
txtA.Text = "";
txtB.Text = "";
txtC.Text = "";
txtAttedence.Text = "";
txtInclass.Text = "";
txtAssignment.Text = "";
txtMidterm.Text = "";
txtFinal.Text = "";
txtOther.Text = "";
lblStatus.Text = "Choose category from list";
lblInstruction.Visible = true;
foreach (int i in CheckList.CheckedIndices)
{
CheckList.SetItemCheckState(i, CheckState.Unchecked);
}
}
}