private void buttonAdd_Click(object sender, EventArgs e)
 {
     if (textBoxExam.Text == "")
     {
         ProcessInvalid(labelExam);
         MessageBox.Show("Exam name can't be empty", "", MessageBoxButtons.OK, MessageBoxIcon.Error);
     }
     else if (textBoxPercentage.Text == "")
     {
         ProcessInvalid(labelFinalPercentage);
         MessageBox.Show("Exam percentage can't be empty", "", MessageBoxButtons.OK, MessageBoxIcon.Error);
     }
     else if (CheckExamExists(textBoxExam.Text))
     {
         ProcessInvalid(labelExam);
         MessageBox.Show("Exam already exists", "", MessageBoxButtons.OK, MessageBoxIcon.Error);
     }
     else
     {
         var exm = new Exam
         {
             ExamName        = textBoxExam.Text,
             FinalPercentage = Convert.ToDouble(textBoxPercentage.Text),
             IsActive        = checkBoxIsActive.Checked
         };
         if (_settingService.AddExam(exm))
         {
             MessageBox.Show("Data Saved Successfully!", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
             ProcessValid(labelExam);
             ProcessValid(labelFinalPercentage);
             gridViewSelectedId = exm.ExamId.ToString();
             LoadDataExam(_settingService.GetExamList());
             dataGridViewExam.Refresh();
         }
         else
         {
             MessageBox.Show("error");
         }
     }
 }