private void SubjectDetailGUI_Load(object sender, EventArgs e)
{
string text = label1.Text;
text += SubjectDAO.getSubjectName_Hoang(subid);
label1.Text = text + " is " + count + " students";
txt1.Text = getTest1(subid);
txt2.Text = getTest2(subid);
txt3.Text = getTest3(subid);
txt4.Text = getFinal(subid);
}